Let GRANT ... ON forms offer schema names as completions

[rolandwalker]

Description

Let GRANT ... ON forms offer schema names as completions instead of only table names.

Fixes #578 .

As the commentary notes, the test fixtures are insufficient to test the change, but it can be verified interactively. See image.

One thing that is confusing in the code is the use of "database" vs "schema". Here the "type" is "database".

Checklist

• I've added this contribution to the changelog.md.
• I've added my name to the AUTHORS file (or it's already there).
• I ran uv run ruff check && uv run ruff format && uv run mypy --install-types . to lint and format the code.

[scottnemes]

Looks good!

Future potential idea; would be nice if tables would also come up for the given schema, but believe that would require additional fetching then (i.e. with no database selected, typing in grant all on mysql. would then fetch the tables from the mysql schema for completion).

[rolandwalker]

Future potential idea

Yes, it looks like there is a lot of room for improvement, especially if we used sqlglot to more deeply examine the structure of the query. Though we might find out that sqlglot is too strict for the case of partial queries.