Allow unquoted comma-containing favorite queries to be saved in ~/.myclirc

[rolandwalker]

Description

ConfigObj returns a list when it sees a comma, so mycli was capable of saving an item it could not read back on restart.

The fix is for values in the favorite_queries stanza to be treated differently, and never to be read in as a list.

Favorite queries are all triple-quoted on save, and there is an on-the-fly hack to the reader to triple-quote any favorite from past saves which are not triple-quoted.

There could be other stanzas of the config file which should have the same treatment.

Shipping this with one minor limitation noted in comments: saving SQL with both possible triple-quote delimiters as values internal to the SQL text is not possible.

Fixes #2339

Checklist

• I added this contribution to the changelog.md file.
• I added my name to the mycli/AUTHORS.txt file (or it's already there).
• To lint and format the code, I ran

  uv run ruff check && uv run ruff format && uv run mypy --install-types .

[rolandwalker]

This is more complex than I'd like it to be. It could be simpler to just entirely turn off ConfigObj's ability to interpret values as lists, and then hand-parse an enumerated list of keys which should have lists as values.