add free-text search extension

[hrodmn]

Related Issue(s):

• add support for free-text extension (in collection search) #153

Description:
This is a pretty simple addition but it is dependent on the next release of pgstac (the pgstac-side changes were added in stac-utils/pgstac#295) so the new test will fail until we decide how to conditionally activate this feature. Would it make sense to only activate this extension if the pgstac version is >0.9.1?

The q parameter should probably never be used in an item search because it will probably slow things down a lot, but it is very useful for the collection search function.

PR Checklist:

• pre-commit hooks pass locally
• Tests pass (run make test)
• Documentation has been updated to reflect changes, if applicable, and docs build successfully (run make docs)
• Changes are added to the CHANGELOG.

[vincentsarago]

@hrodmn I would love to first finish #155 which I think is going to be dependent on 0.9.2 (at least on the tests side)

[hrodmn]

Now that pgstac 0.9.2 is released (with support for the q free-text parameter) I wanted to kick the tires on this PR! The tests will only pass if we are running pgstac >= 0.9.2 so I'm not exactly sure what that means for releasing this feature.

[vincentsarago]

The q parameter should probably never be used in an item search because it will probably slow things down a lot, but it is very useful for the collection search function.

@hrodmn should we then remove it from the extensions_map list ?

if we keep it, could you add some tests for it? 🙏

[hrodmn]

should we then remove it from the extensions_map list ?

Yes, I think removing it from the list of item search extensions by default is the way to go. Users could add it in custom applications if it would be helpful. It's all supported in core.py so I should add some tests to make sure it is working correctly.

Update: Actually free-text for item search is not really supported because pgstac will only search through the description, title, and keywords fields which are not even in the STAC item spec. I will remove the q parameter from the item search request methods to avoid confusing people.