New analyzer + codefix: Remove no-op Select statements

Sadly in code I often see things like this:

```
var y = collection.Select(x => x);
```

This does nothing except waste CPU cycles. An analyser and refactoring to remove these aberrations would be nice.

No files, tests, or entry points are named in the issue. Start by locating the existing analyzer and codefix structure in the repository, then use the provided collection.Select(x => x) example to determine the expected diagnostic, transformation, and test coverage; done means the no-op Select is identified and safely removable.

Written by the indexing model from the issue text.