Fix Solo defaults

[robertlong13]

Chipping away at out-of-date param files. Started with the Solo boards as the lowest-hanging fruit.

This technically also touches luminousbee5, but in a pretty non-intrusive way (it also still doesn't pass; that will be my next PR).

Fixes:

• BRD_SAFETYENABLE
  • luminousbee5 actually had fixed this already, but didn't remove the old param, just added the new
• MNT Params
• Removed INS_GYR_FILTER. This is missing an "O". It was added 5 years ago in #13226, but it didn't work back then either. I have removed it instead of fixing it so that I'm not actually changing current behavior.
• Removed PILOT_TKOFF_DZ. Apparently this never did anything
• Updated references to the recently-renamed SR parameters