🎉 🪟 [Connector Builder] Resolve manifest before converting to builder form values

[lmossman]

What

Closes #21610

Now that we have an endpoint in the connector builder server to resolve all $refs and $options in a manifest, this PR makes the connector builder call that endpoint on the YAML manifest in the editor before converting it to UI.

How

• Add useResolveManifest to the ConnectorBuilderApiService to make the new endpoint usable
• Change manifestToBuilderForm.ts to a custom hook useManifestToBuilderForm.ts, since it needs to use the useResolveManifest() hook now
• Modify convertToBuilderFormValues to call the resolve endpoint at the beginning of the function, and use the result in the rest of the conversion
• The above change resulted in that method becoming async, so update its usages and the tests to be async as well

[lmossman]

A lot of small async/await changes in this file, since convertToBuilderFormValues is now an async function

[flash1293]

This is super nice! Trying this with real manifest I found a few generic issues in our conversion code: https://docs.google.com/document/d/1694N09qm839yEtsSrGfC1ptDCickVm9cQWsSYBSiT-Q/edit?usp=sharing

I don't think we need to solve all of them and most likely on a separate PR, but in order to make the "upload a yaml file" CTA useful I think we should solve the most critical ones.

If you agree I can split it into issues

[lmossman]

@flash1293 thanks for compiling this! I agree we should solve these, though I think we can merge this PR in in its current state and split the doc into tickets as you suggested 👍

[flash1293]

I think something went wrong with the auto-formatting

[lmossman]

Woah, yep you're right. I'll work on fixing

[lmossman]

@flash1293 this should be fixed now

[flash1293]

LGTM