CodeFix and Diagnostic for Unnecessary Named Import

[sidlamsal]

Fixes #56497

[sidlamsal]

@microsoft-github-policy-service agree

[jakebailey]

This PR says it fixes #56497, but that's not entirely the case; #56497 is asking for rename to not introduce foo as foo at all, whereas this PR adds a new suggestion that complains about foo as foo. That's a fine suggestion, but I would expect a PR that fixes #56497 to fix rename, and IIRC there's something odd about the way renaming works that may prevent that from working (but I can't remember what it was; I've wanted to fix this issue previously but gave up due to some issue...).

[sidlamsal]

@jakebailey, understood. I came to a similar conclusion when trying to get rename to not include the redundancy. Would it be acceptable to create a new issue to close via this PR? Because, this PR has a lightweight band-aid "fix" for a non code-breaking bug. If not, do you have any insight/suggestion on fixing rename itself?