fix: validate predicate start_block and end_block - #489

### Description

Previously, the scanning threads had some validation for the
`start_block` and `end_block` that was incorrect. This PR introduces
validation that does the following:
- We now allow `start_block` to be omitted by the user and we default to
0
- If there are no blocks in the database, we abort the scan and go to
streaming mode rather than erroring (fixes #477)
- If the user provides an `end_block`, we validate that it is greater
than the `start_block`
- If the `start_block` is greater than chain tip, we abort the scan and
go to streaming mode rather than erroring (fixes #464)

This PR also adds some validation to the `BlockHeights` class.
Previously, it was possible to overload the
`BlockHeights::BlockRange(start_block, end_block)` function to allocate
a lot of memory into an empty array. We now have limits on this class.
However, due to the above validation, it should not be possible to pass
through parameters that reach theses limits (with the current usage of
the class) until a chain height is up to `1_000_000`.

---

### Checklist

- [x] All tests pass
- [x] Tests added in this PR (if applicable)

## [1.3.0](v1.2.1...v1.3.0) (2024-02-08)

### Features

* optionally serve Prometheus metrics ([#473](#473)) ([67a38ac](67a38ac))

### Bug Fixes

* adjust ordinal_number entry in ts client inscription transfer event, add new reveal data ([#476](#476)) ([28bf5c4](28bf5c4))
* remove early return for event evaluation ([#484](#484)) ([98f9e86](98f9e86)), closes [#469](#469)
* remove unreachable panic; return instead ([#490](#490)) ([abe0fd5](abe0fd5))
* use cli feature for `cargo chainhook-install` ([#486](#486)) ([32f4d4e](32f4d4e))
* validate predicate `start_block` and `end_block` ([#489](#489)) ([e70025b](e70025b)), closes [#477](#477) [#464](#464)

## [1.3.0](hirosystems/chainhook@v1.2.1...v1.3.0) (2024-02-08)

### Features

* optionally serve Prometheus metrics ([#473](hirosystems/chainhook#473)) ([67a38ac](hirosystems/chainhook@67a38ac))

### Bug Fixes

* adjust ordinal_number entry in ts client inscription transfer event, add new reveal data ([#476](hirosystems/chainhook#476)) ([28bf5c4](hirosystems/chainhook@28bf5c4))
* remove early return for event evaluation ([#484](hirosystems/chainhook#484)) ([98f9e86](hirosystems/chainhook@98f9e86)), closes [#469](hirosystems/chainhook#469)
* remove unreachable panic; return instead ([#490](hirosystems/chainhook#490)) ([abe0fd5](hirosystems/chainhook@abe0fd5))
* use cli feature for `cargo chainhook-install` ([#486](hirosystems/chainhook#486)) ([32f4d4e](hirosystems/chainhook@32f4d4e))
* validate predicate `start_block` and `end_block` ([#489](hirosystems/chainhook#489)) ([e70025b](hirosystems/chainhook@e70025b)), closes [#477](hirosystems/chainhook#477) [#464](hirosystems/chainhook#464)