Fix distinct (infiniflow#3246)

### What problem does this PR solve?

Support the following distinct:
1. select distinct c1,c2 from t1;
2. select distinct c1,c2 from t1 order by c1;
3. select count(distinct c1,c2) from t1;
4. select sum(distinct c1) from t1;
5. select distinct cast(c1 as integer)  from t1;


test: test_distinct.slt

Issue link:infiniflow#3211

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Update version to 0.7.0.dev2 (infiniflow#3220)

### What problem does this PR solve?

As title

### Type of change

- [x] Documentation Update
- [x] Other (please describe): update version

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

Update version info to 0.7.0.dev1 (infiniflow#3213)

### What problem does this PR solve?

Update version to 0.7.0.dev1, Python SDK also update to new version.

### Type of change

- [x] Documentation Update
- [x] Python SDK impacted, Need to update PyPI

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

update version 0.6.15 (infiniflow#3192)

### What problem does this PR solve?

As title

### Type of change

- [x] Documentation Update
- [x] Python SDK impacted, Need to update PyPI

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

Fix message error, sdk error and explain error (infiniflow#3191)

### What problem does this PR solve?

1. Fix part of version info error
2. SDK explain statement missing sort
3. search expr won't show in explain AST

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

Fix bug and update version (infiniflow#3190)

### What problem does this PR solve?

1. Fix pysdk release bug
2. update version to 0.6.13

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

Update version info to v0.6.12 (infiniflow#3177)

### What problem does this PR solve?

Update version to v0.6.12

### Type of change

- [x] Other (please describe):

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

Update version info to v0.6.12 (infiniflow#3177)

### What problem does this PR solve?

Update version to v0.6.12

### Type of change

- [x] Other (please describe):

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

Update version to v0.6.11 (infiniflow#3147)

### What problem does this PR solve?

As title

### Type of change

- [x] Other (please describe): Update version

---------

Co-authored-by: Zhichang Yu <yuzhichang@gmail.com>

Update version info to 0.6.10 (infiniflow#3133)

### What problem does this PR solve?

Update version info to 0.6.10

### Type of change

- [x] Other (please describe): Update version

Signed-off-by: Jin Hai <haijin.chn@gmail.com>