[lua, sql][Module] BRD, DRG, and spell era module adjustments

[CriticalXI]

I affirm:

• I understand that if I do not agree to the following points by completing the checkboxes my PR will be ignored.
• I understand I should leave resolving conversations to the LandSandBoat team so that reviewers won't miss what was said.
• I have read and understood the Contributing Guide and the Code of Conduct.
• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

• Reorganizes spell related modules to be in their own spell_adjustment module rather than categorized by job.
• Adds Bio and Dia adjustments to reduce the respective attack and defense down effects.
• Adds Bard merit and mazurka adjustments to the existing modules. Also populated a TODO for pending song buff value adjustments that are pending global adjustments to magic tables.
• Prelude, Etudes, Foe Sirvente, and Adventurer's Dirge set to single target and reduced cast time
• Adds missing DRG era adjustment to wipe wyvern's current TP when they use an elemental breath
• Adjusts cast times for Protectra, Shellra, and Regen.

Steps to test these changes

• Load all affected modules in init.txt
• Test the listed abilities or spells in game to see the commented logic occurs