Failed source schema updates appear successful in the UI

[teallarson]

On the Connection page:

Currently if there is an error response on the POST when a user clicks "refresh source schema", there is no indication to them. It looks to the user as though the refresh completes successfully with no changes in the Source. When the loading screen is done, the refresh button goes away and there is the "if you save this it overrides things" warning, just like if the refresh had been successful (in the above screenshot, there had been a 500 error in the refresh source schema. the schema shown on the screen does not match the actual source schema as a result of the call failing)

We should surface that there was an error refreshing the schema and treat it as if there had not been a successful schema update (ie: the "refresh source schema" button should be visible).

[octavia-squidington-iii]

cc @airbytehq/frontend

[teallarson]

@krishnaglick this seems like it might be reasonable to fold into when we address the "refresh source schema" logic? I don't want to introduce scope creep, but seems like it could be small to implement.