Rare weapon changes and additions

[MMM]

The named rare weapons, which were originally very individual across the same weapon rank, have been reworked to include a more common theme among each weapon and hopefully become more balanced. In addition, some common weapon drops have been introduced as well. All changes made were as follows:

- For treasure level 1, E-rank rares now consist of: Horse- and Armorslaying weapons (similar to the Rapier in main FE games) for physical melees, a mini-Longbow for bows, MArmorslayers for tomes, and a ranged version of Fortune for staves.
- For treasure level 2, D-rank rares feature Brave weapons for all physical weapon types and status weapons for magic, with staves getting a ranged version of Shield.
- For treasure level 3, C-rank rares feature Flierslayers across all weapon types except for Bows and Staves. Bows get a 3-5 range ballista that inflicts the Freeze status, and Staves get a ranged version of Ward.
- For treasure level 4, B-rank rares feature ranged twin weapons with an elevated crit rate for physical melees, a critty Longbow, 2-3 range tomes, and a miniature version of the Miracle staff.
- For treasure level 5, A-rank rares feature superior versions of twin weapons (range locked for all weapon types including magic) along with the previously existing Deadlies/Siege weapons and Mila's Protection, which is currently the only staff that grants the Protect buff.
- For treasure levels 5 and 6, A-rank Horseslayers and (M)Armorslayers were introduced, which should be self-explanatory.

For those of you who have been in unenjoyable situations before due to some of these rare weapons being overpowered, we hope that this addresses such issues and that you keep enjoying FETO!