Merged PRs

dolt

7895: prevent filter-branch when there are local changes
This PR changes filter-branch to detect any local changes so working/staged changes aren't lost.
A future PR should include changes to have the working set just be applied over the result of dolt filter-branch.
partially addresses: #7891

2512: Spooling shortcut for one/zero return schemas
Nodes that return zero or one row don't need a beefy channel/wait group setup to execute. They just need to grab the first row and close the iterator. There are several nodes that incorrectly reported their schemas previously, which I've updated to be more accurate. There are some nodes that optionally return rows, which I've simplified to return an empty schema that can be differentiated from the nil schema. We could make the distinction more explicit, also.
bump with perf here: #7894
2511: Adding mapping to error code 1049 for ErrDatabaseNotFound errors
When a database doesn't exist, MySQL returns error code 1049. This change adds a mapping to error code 1049 for ErrDatabaseNotFound errors, and updates our handler so that ComInitDB messages will map errors to MySQL error codes.
This is needed because tooling (e.g. Pomelo EntityFramework MySQL library) can rely on this error code in application logic.
Related to #7890