feat(web): support reversion of accepted suggestions after edits 🖲️

[jahorton]

The work in this PR corresponds to this idea: #12648 (comment)

When typing rapidly, one often does not notice if the autocorrect chose wrongly. Backspacing to undo autocorrect only seems to work immediately after the spacebar is pressed; once any other keys are pressed, you have to delete the entire word and retype.

For this one... I think the "context tracker" system could, in theory, be leveraged to detect this case with some additional work. We're basically looking to revert the suggestion after a delay in this case, rather than immediately after its application. This is also presently a limitation outside of autocorrect, so it's something I could look into for the current release cycle if desired.

This PR should have user testing done on it once ready; the behavior it'll add will be user-facing.

[keymanapp-test-bot]

User Test Results

Test specification and instructions

ERROR: user tests have not yet been defined