During the "generalization" of the code, we removed the [generated instances](9d63187803 (diff-7b8382ab20e441fa214586be491eb6f7ca904d8b20ed97894c16a339be45219aL72)) of `Eq` and `Hashable` in favour of manually written ones, because for a time we were struggling with `AnyBackend`.
In the process, we lost one constructor, `MOEndpoint`. It's unlikely to have ever been an issue, since duplicate endpoints are unlikely, but it is nonetheless wrong.
This PR simply goes back to default derived instances, now that we can, fixing the problem and making the code simpler.
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However, after filing this PR, I realized **it broke rest endpoint tests**. Upon closer inspection, it turns out that while we had proper checks in place, because of this bug we were actually failing _differently_ during metadata checks. This PR actually improves error messages for invalid endpoint configurations?! 🙀
This is a tiny bit scary. ^^'
https://github.com/hasura/graphql-engine-mono/pull/1762
GitOrigin-RevId: c4897d1f3ae92d18c44c87d2f58258c66f716686
Previously invalid REST endpoints would throw errors during schema cache build.
This PR changes the validation to instead add to the inconsistent metadata objects in order to allow use of `allow_inconsistent_metadata` with inconsistent REST endpoints.
All non-fatal endpoint definition errors are returned as inconsistent metadata warnings/errors depending on the use of `allow_inconsistent_metadata`. The endpoints with issues are then created and return informational runtime errors when they are called.
Console impact when creating endpoints is that error messages now refer to metadata inconsistencies rather than REST feature at the top level:
<img width="969" alt="image" src="https://user-images.githubusercontent.com/92299/110258597-8336fa00-7ff7-11eb-872c-bfca945aa0e8.png">
Note: Conflicting endpoints generate one error per conflicting set of endpoints due to the implementation of `groupInconsistentMetadataById` and `imObjectIds`. This is done to ensure that error messages are terse, but may pose errors if there are some assumptions made surrounding `imObjectIds`.
Related to https://github.com/hasura/graphql-engine-mono/pull/473 (Allow Inconsistent Metadata (v2) #473 (Merged))
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### Kodiak commit message
Changes the validation to use inconsistent metadata objects for REST endpoint issues.
#### Commit title
Inconsistent metadata for REST endpoints
GitOrigin-RevId: b9de971208e9bb0a319c57df8dace44cb115ff66
