Standardize loot order/styling across the addon

[snowflame0]

Is your feature request related to a problem? Please describe.
A lot of the loot tables' ordering is inconsistent, from many different contributors over the years. Leading to many tables looking messy. I'm guilty of it myself, can't make up my mind sometimes when laying out a table.

Describe the solution you'd like
Need to:

1. Standardize some layout guidelines like loot order by slot or armor type, etc, toys, achievements, currencies.
2. Retroactively update all the loot tables.
3. Post design guidelines in Github Wiki and have contributors abide by it.
4. Maybe just restructure the code that lays out tables to make it do most of this automatically.

Additional context
Any suggestions welcomed.