Import MySQL completion candidates from pygments

[rolandwalker]

Description

Since the pygments library is already required, why not use its list of reserved words for completions?

This fixes #767 and should keep us up-to-date. It's really great to have the JSON_* functions.

Obsoletes #925, and addresses the two points in #925 (comment) .

Compared to the previous code, this PR

• removes LEN and TOP, which are not MySQL reserved words
• preserves extra completion candidates containing space, such as ORDER BY

Downsides and bugs:

• pygments.lexers._mysql_builtins does contain a leading underscore, so we should be aware that the library reserves the right to break this usage. The library version has been more tightly defined to remediate issues here.
• Similarly, certain tests might become more brittle with regard to library updates.
• Certain reserved words are duplicated with special commands, so if the first word of a command-line is any of the following, duplicated completions will show, as both upper- and lower-case: exit, help, source, status, system, use. This is fixable, but should we prefer the upper- or lower-case flavor?
• There are many more completion candidates now, which may inspire us to do further work soon on prioritizing which completions are seen at the top.

Checklist

• I've added this contribution to the changelog.md.
• I've added my name to the AUTHORS file (or it's already there).
• I ran uv run ruff check && uv run ruff format && uv run mypy --install-types . to lint and format the code.

[scottnemes]

This is fixable, but should we prefer the upper- or lower-case flavor

I always prefer lowercase, but as long as it's consistent; i.e. all options, regardless of source, are uppercase or lowercase ideally.

[scottnemes]

While looking at your follow-up PR, I noticed these get duped, I.e.:

Is that desired?

[scottnemes]

Never mind I realized it makes sense in the context of you technically don't know if they want just the keyword master, or the command change master to in this example. Was overthinking it since there is no valid "change master" command, but that is another layer of context.

Added comment

[rolandwalker]

This is fixable, but should we prefer the upper- or lower-case flavor

I always prefer lowercase, but as long as it's consistent; i.e. all options, regardless of source, are uppercase or lowercase ideally.

I'll make lowercase duplicates preferred in a followup PR.