Minor database error logging improvements

[AuroraLS3]

I would like to be able to..

Reduce support strain from two common exceptions being pasted to discord.

Is your feature request related to a problem? Please describe.

1. When plugin enables and attempts to connect to MySQL, it will give an error along the lines of "Connection refused, last packet was 0ms ago (has not received any packets)" - This message is difficult to understand for non-English speakers and does not include instructions how to fix it.

• Include instructions on how to fix it:
• Double check these settings: (list settings and current values (except password) "that database with name 'Plan' (from config) exists"
• Detect pterodactyl if possible and put mysql instructions link, as well as recommended IP format to use (ask somebody who has it setup)

2. Change wiki instructions for Bungee to not reload Plan until step 2 is complete (So that MySQL settings are also included in reload)
3. When plugin disables and database shuts down, but some queries are ongoing, an exception is thrown and logged. This exception says something like "Database is closed (This exception is thrown to not block the thread)". It is confusing to the user and leads to them reporting the wrong exception, since this isn't the root cause for the issue.

• Change the type of thrown issue and ignore it in the error logger.
• Make sure that any EnableException's that come from DBOpException catch blocks try to get the real cause or at least write some kind of message about it.