fix(stac-api): avoid base64 encoding application/geo+json data

[alukach]

When using a REST API with a Lambda Proxy integration (such as when making use of our PrivateLambdaApiGateway, link), data that Mangum converts to base64 is not converted to text by the API Gateway.

By default, Mangum v0.14.1 converts any text data to base64 aside from its builtin defaults¹. These defaults do not include application/geo+json which is used by the STAC API. This PR upgrades Mangum (by utilizing stac-fastapi-pgstac's unspecified mangum version²) and configures Mangum to avoid converting any data to base64 that begins with text/ or application/.

Question: Perhaps we should just disable the base64 conversion completely by specifying a text mime type of '' which would match all mime_type in content_type³ lookups?

Footnotes

1. https://github.com/Kludex/mangum/blob/0.14.1/docs/http.md#text-mime-types ↩

2. https://github.com/stac-utils/stac-fastapi-pgstac/blob/d43ea548103d0e157d7e22fb70f9ea9fe310509b/setup.py#L49C6-L49C15 ↩

3. https://github.com/Kludex/mangum/blob/0.14.1/mangum/handlers/utils.py#L79 ↩

[gadomski]

I don't know, this feels a little overbroad ... Could we just add the GeoJSON mime type instead?

[alukach]

Yes, but there's also the Open API spec with application/vnd.oai.openapi;version=3.0. Your point regarding Parquet is valid though, would that have application/vnd.apache.parquet? And we probably wouldn't want to convert application/octet-stream either...

[gadomski]

Perhaps we should just disable the base64 conversion completely by specifying a text mime type of '' which would match all mime_type in content_type3 lookups?

Not sure... We might as stac-geoparquet (or some other binary format) responses down the road, in which case we might want the conversion?