## Description
This PR removes `MetadataStorageT`, and cleans up all top-level error handling. In short: this PR changes `MonadMetadataStorage` to explicitly return a bunch of `Either QErr a`, instead of relying on the stack providing a `MonadError QErr`. Since we implement that class on the base monad *below any ExceptT*, this removes a lot of very complicated instances that make assumptions about the shape of the stack.
On the back of this, we can remove several layers of ExceptT from the core of the code, including the one in `RunT`, which allows us to remove several instances of `liftEitherM . runExceptT`.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7689
GitOrigin-RevId: 97d600154d690f58c0b93fb4cc2d30fd383fd8b8
We currently have a fairly intricate way of running our PostgreSQL and MSSQL integration tests (not the API tests). By splitting them out, we can simplify this a lot. Most prominently, we can rely on Cabal to be our argument parser instead of writing our own.
We can also simplify how they're run in CI. They are currently (weirdly) run alongside the Python integration tests. This breaks them out into their own jobs for better visibility, and to avoid conflating the two.
The changes are as follows:
- The "unit" tests that rely on a running PostgreSQL database are extracted out to a new test directory so they can be run separately.
- Most of the `Main` module comes with them.
- We now refer to these as "integration" tests instead.
- Likewise for the "unit" tests that rely on a running MS SQL Server database. These are a little simpler and we can use `hspec-discover`, with a `SpecHook` to extract the connection string from an environment variable.
- Henceforth, these are the MS SQL Server integration tests.
- New CI jobs have been added for each of these.
- There wasn't actually a job for the MS SQL Server integration tests. It's pretty amazing they still run well.
- The "haskell-tests" CI job, which used to run the PostgreSQL integration tests, has been removed.
- The makefiles and contributing guide have been updated to run these.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6912
GitOrigin-RevId: 67bbe2941bba31793f63d04a9a693779d4463ee1
