Make cql2_like_to_es() understand escaped backslashes

[kurtmckee]

Related Issue(s):

• Closes cql2_like_to_es() does not correctly convert #285

Description:

This is a break/fix PR. The first commit adds a suite of tests that document correct LIKE-to-wildcard query value conversions, and then fixes the cql2_like_to_es() code to correctly process escaped backslashes.

PR Checklist:

• Code is formatted and linted (run pre-commit run --all-files)
• Tests pass (run make test)
  (make test fails because the Docker container port ranges don't match, but CI, which doesn't use make test, passes)
• Documentation has been updated to reflect changes, if applicable
  n/a, no docs in repo
• Changes are added to the changelog

[jamesfisher-geo]

Hi @kurtmckee. Thanks for the PR. After opening a PR you should add a reference to the PR in the changelog here.

There have not been any changes since the 3.0.0 release, so you should add an "Unreleased" section to the top of the list like so.

## [Unreleased]

### Changed
- <description> [#286](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/286)

[jamesfisher-geo]

You can find the current API tests for LIKE search in the filter extension tests: https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/blob/main/stac_fastapi/tests/extensions/test_filter.py#L260-L353

In terms of filter documentation, there is none in this repo. But a list of the supported methods would be useful I'm sure. Plus a pointer to the examples and filter extension documentation, which has a lot of great examples too.

[kurtmckee]

I've updated the CHANGELOG to include this change. 👍

Please let me know if anything else is missing for this PR!

[jamesfisher-geo]

This looks good. Thanks @kurtmckee!

[jonhealy1]

Great work