Add a "fix all" button for repeated errors in a document.

## Description

Sometimes one mistake that a linter picks up is repeated over and over throughout a document. Perhaps throughout a codebase:

It would be nice to have a button to fix all occurrences of the same error.

## Component

Definitely applies to the VS Code extension, but I'm pretty sure that's due to how things like code actions and such work at a lower level. I haven't really looked into this area of the code.

No file or test is named. Start by tracing the VS Code extension's code-action handling, then determine how repeated instances of one linter error are identified. Done means the extension offers a fix-all action that applies the same correction to every occurrence in the document.

Written by the indexing model from the issue text.