Bug fixes, QOL tweaks, and code clean up.

[x] I have tested my changes against the dev branch (the latest developmental version), and this pull request is targeting that branch as a base
[x] I have tested my changes on Python 3.10 or higher
[x] I have ensured my code is formatted using Black

This PR will leave dev in a working state! :tada:
It contains the following note worthy changes and fixes:

Adds support for commands by mention, E.g.: @MusicBot search instead of command prefix only.
- See the CommandsByMention option to enable.
Adds support for dynamic variables in custom status messages.
- See the updated help text in example_options.ini for usage details.
Adds http based network testing as a fall back for systems without access to ping when network testing is desired.
Command config no longer requires the section argument. (as long as duplicate options don't happen in the future)
Command blockuser can work on non-guild member mentions as well as ID strings to avoid mentions.
- Additional command argument ? or status will show a users blocked status.
Fix typo in permissions that broke the CommandWhitelist/CommandBlacklist options.
Possible fix for high CPU bug caused by race condition that resulted in an infinite loop.
Fix for disconnect handling while auto-join is configured.
A hand full of stuff that didn't make it into the last PR, which left it broken.
Various comment updates and removal of old code.

Could close #2399

Just-Some-Bots / MusicBot