no-panic mode for client-side metadata handling/validation

[soxofaan]

The openeo python client does (client-side) validation of some things (e.g. when filtering bands, are the specified bands valid?), in the spirit of catching errors as soon as possible (e.g. before submitting a job) to have a quick feedback loop.

However, in practice we have situations where the client sometimes fails too panicky about things that will be handled by the backend anyway. For example: client side detection of bands in STAC resources is not as complete (or different) from back-end side handling.

There should be some escape hatch to disable this kind of validation when necessary

[soxofaan]

• Avoid unnecessary UserWarning: No cube:dimensions metadata #315

[soxofaan]

Another work mode that could be covered here: provide a way to skip all metadata fetching/parsing/validation.

reasoning: validation and warnings are interesting when developing a workflow interactively. But when workflow scripts are executed in some kind of unattended fashion, it's wasteful to do all the same metadata requests over and over.