test(contrib/drivers/mysql): add pagination and error handling tests - #4703

## Summary
Fix bug where AllAndCount(true) with multiple fields generates invalid
SQL COUNT(field1, field2, ...) causing syntax error.

## Root Cause
When useFieldForCount=true, the COUNT query inherits the fields
configuration from the model, generating COUNT(multiple fields) which
is invalid SQL syntax.

## Fix
Always use COUNT(1) regardless of useFieldForCount parameter since
COUNT() accepts only one argument.

Applied to both AllAndCount() and ScanAndCount() methods in
database/gdb/gdb_model_select.go.

## Tests
Added Test_Issue4698 in contrib/drivers/mysql/mysql_z_unit_issue_test.go
with 5 test cases covering all scenarios.

Updated SQLiteCGo tests to expect correct behavior after framework fix.

Fixes gogf#4698
Ref gogf#4703

## Summary
Fix bug where AllAndCount(true) with multiple fields generates invalid
SQL COUNT(field1, field2, ...) causing syntax error.

## Root Cause
When useFieldForCount=true, the COUNT query inherits the fields
configuration from the model, generating COUNT(multiple fields) which
is invalid SQL syntax.

## Fix
Always use COUNT(1) regardless of useFieldForCount parameter since
COUNT() accepts only one argument.

Applied to both AllAndCount() and ScanAndCount() methods in
database/gdb/gdb_model_select.go.

## Tests
Added Test_Issue4698 in contrib/drivers/mysql/mysql_z_unit_issue_test.go
with 5 test cases covering all scenarios.

Updated SQLiteCGo tests to expect correct behavior after framework fix.

Fixes gogf#4698
Ref gogf#4703

## Summary
Fix bug where `Fields("")` with empty string generates invalid SQL
`SELECT FROM table`.

## Root Cause
`mappingAndFilterToTableFields` method doesn't skip empty strings when
processing fields:
- `gstr.SplitAndTrim("", ",")` returns empty array
- No fields added to query
- Results in invalid SQL: `SELECT FROM table`

## Fix
Skip empty string fields in `mappingAndFilterToTableFields` (line
97-100):
```go
// Skip empty string fields
if fieldStr == "" {
    continue
}
```

## Behavior Changes
- `Fields("")` → SELECT * FROM table (uses default)
- `Fields("", "id")` → SELECT id FROM table (ignores empty string)
- `Fields("id", "", "nickname")` → SELECT id, nickname FROM table

## Tests
Added `Test_Issue4697` with 3 scenarios covering all cases above.

## Related
Fixes #4697
Ref #4703 (discovered during pagination test development)

Fix bug where AllAndCount(true) with multiple fields generates invalid
SQL COUNT(field1, field2, ...) causing syntax error.

When useFieldForCount=true, the COUNT query inherits the fields
configuration from the model, generating COUNT(multiple fields) which
is invalid SQL syntax.

Always use COUNT(1) regardless of useFieldForCount parameter since
COUNT() accepts only one argument.

Applied to both AllAndCount() and ScanAndCount() methods in
database/gdb/gdb_model_select.go.

Added Test_Issue4698 in contrib/drivers/mysql/mysql_z_unit_issue_test.go
with 5 test cases covering all scenarios.

Updated SQLiteCGo tests to expect correct behavior after framework fix.

Fixes gogf#4698
Ref gogf#4703

…4702)

## Summary
Fix bug where negative values in `Limit()`, `Page()`, and `Offset()`
methods generate invalid SQL causing database errors.

## Root Cause
The methods don't validate negative input:
- `Limit(-1)` generates `LIMIT -1` → SQL error
- `Page(1, -10)` generates `LIMIT -10` → SQL error  
- `Offset(-5)` generates `OFFSET -5` → SQL error

## Fix
Treat all negative values as zero (safe default):

**Limit() method**:
```go
case 1:
    if limit[0] < 0 { limit[0] = 0 }
case 2:
    if limit[0] < 0 { limit[0] = 0 }
    if limit[1] < 0 { limit[1] = 0 }
```

**Page() method**:
```go
if limit < 0 { limit = 0 }
```

**Offset() method**:
```go
if offset < 0 { offset = 0 }
```

## Behavior Changes
- `Limit(-1)` → `Limit(0)` (no limit)
- `Limit(-10, -5)` → `Limit(0, 0)` (no offset, no limit)
- `Page(1, -10)` → `Page(1, 0)` (no results)
- `Offset(-5)` → `Offset(0)` (no offset)

## Documentation
Added "Note: Negative values are treated as zero" to all three methods.

## Tests
Added `Test_Issue4699` in `database/gdb/gdb_z_unit_issue_test.go` with 7
test cases:
1. Limit with single negative parameter
2. Limit with two negative parameters
3. Limit with mixed parameters (negative start, positive limit)
4. Page with negative limit
5. Page with negative limit on page 2
6. Offset with negative value
7. Offset with positive value (sanity check)

## Related
Fixes #4699
Ref #4703 (discovered during pagination test development)

…n when parameter `useFieldForCount` is true in AllAndCount/ScanAndCount (#4701)

## Summary
Fix bug where `AllAndCount(true)` with multiple fields generates invalid
SQL `COUNT(field1, field2, ...)` causing syntax error.

## Root Cause
When `useFieldForCount=true`, the COUNT query inherits the fields
configuration from the model:
```go
// Before (buggy code)
if !useFieldForCount {
    countModel.fields = []any{Raw("1")}
}
// When useFieldForCount=true, fields remain as ["id", "nickname"]
// Generates: SELECT COUNT(id, nickname) FROM table ❌
```

## Fix
Always use `COUNT(1)` regardless of `useFieldForCount` parameter since
COUNT() accepts only one argument:
```go
// After (fixed code)
// Always use COUNT(1) for counting, regardless of useFieldForCount.
// COUNT() accepts only one argument, so we can't use multiple fields.
countModel.fields = []any{Raw("1")}
```

Applied to both `AllAndCount()` and `ScanAndCount()` methods.

## Tests
Added `Test_Issue4698` with 5 test cases:
1. AllAndCount(true) with multiple fields
2. AllAndCount(false) with multiple fields (baseline)
3. ScanAndCount with multiple fields
4. AllAndCount with single field
5. AllAndCount with WHERE condition

All tests verify that COUNT generates valid SQL and returns correct
count.

## Related
Fixes #4698
Ref #4703 (discovered during pagination test development)