Fixes for php 7.4, MySQL 8, and image servers

[Frug]

With a few tweaks I've been able to run the killboard on PHP 7.4 and MySQL 8 (without changing any of the strictness settings in MySQL). All my inventory images were borked so I included a fix for that, too.
Maybe someone still running a killboard will find these changes useful. The commit history describes the changes, but I realize this should probably be several PRs rather than one.

A few fixes of note:

• Removed a broken API call to ESI that used to fetch the remote alliance ID. That needs to be rewritten to fix it. All I did was remove the broken call. Alliance IDs still won't get updated properly.
• Updated to use CCP's newer image server, and updated the paths to the images so it actually works
• Fixed a few deprecation warnings.
• Fixed several GROUP BY clauses that were missing non-aggregate fields
• Did a bunch of work on the kill list (class.killlist.php) after fixing the GROUP BY clause led me down a rabbit hole to get the right columns listed.

NOTE: When running the updates, the migrations crashed because some default timestamps were set to 0000-00-00 00:00:00. I assume MySQL used to let you use that as a date, but these days it complains if you try to alter a table with a default like that. I manually set a proper default of a random date, but didn't actually write a migration to fix that for you. It only comes up if you try to run the updates from before 032 on MySQL 8.

[tonytonyistony]

@Frug Id like to speak with you about this implementation. Im having some issues trying to get this working on my server and would like to brainstorm. How can I reach you?

[Frug]

@Frug Id like to speak with you about this implementation. Im having some issues trying to get this working on my server and would like to brainstorm. How can I reach you?

Sorry I haven't been very active here. What kind of issues are you having?