Break out STAC Ingestor codebase into separate repo

Currently, we store the STAC Ingestor codebase alongside the STAC Ingestor CDK construct. This means that if a user wants to customize the STAC Ingestor, they need to copy/replicate the STAC Ingestor codebase into a separate repo, customize it, and then recreate the logic around the StacIngestor construct. A better scenario would be to be able to provide the construct an argument that represents a pip-friendly location the codebase can be installed from. I am not certain of the best way to do this.

First pass at a solution

Currently, we are using the PythonFunction construct which requires that a user pass in a directory where either a Pipfile.lock, poetry.lock, or requirements.txt file can be found (source).

It seems like something along the lines of the following may work: Create a custom construct that took in the identifier of an installable module, wrote that to a requirements.txt file, and then passed the path of that requirements.txt file to the Python Lambda to be built. I'm not sure how we could support the customization of the entry and handler arguments...