allow external API gateway to invoke STAC API lambda

[emileten]

Part of https://github.com/NASA-IMPACT/active-maap-sprint/issues/590. It depends on https://github.com/developmentseed/cdk-pgstac/pull/43 being merged.

• [x] allowing a (user-provided) API gateway to invoke the STAC API lambda function. The use case is, getting a functional HTTP lambda integration between an API gateway that lives in the UAH account and this lambda function that lives in the SMCE account, in order to fix https://github.com/NASA-IMPACT/active-maap-sprint/issues/590.

[emileten]

The corresponding cdk-pgstac PR is merged and the release was made. I bumped cdk-pgstac's version here and deployed to test & verified functionality.

Since this is a minor change I am merging before approvals : I would like to integrate this change to the other bigger one I am doing simultaneously https://github.com/MAAP-Project/maap-cdk-pgstac/pull/3.

[emileten]

Agreed 👍