Feature: hide spackbot comments as resolved when appropriate

[wdconinc]

Looking at e.g. spack/spack#46085 (comment), it would be great if spackbot fix style could hide as resolved the following comments (only upon succesful application of style fixes):

• the comment that instructed it, if it was a one liner,
• the comment from spackbot saying "let me see if I can fix that for you",
• the comment from spackbot with the report, if it was successful.

This would keep PRs a bit more readable. Same thing could apply to other commands.