Some refactoring required for proper unit database integration

I am working on the [new unit database](https://faforever.github.io/etfreeman-db/#/URL0001,XSS0201,XSL0202,UES0201) and it requires to extract all balance-related numbers, including some default constants (default shield overspill, veterancy modifiers, etc)

But aeon TMD flare is very hostile-written to do that
The max number of missiles deflected is [hardcoded in if statement](https://github.com/FAForever/fa/blob/45ea30ea792135955f2021d613455ad9b2e7ea42/lua/defaultantiprojectile.lua#L83) and the max radius of deflection [is encrypted in the loop calculations](https://github.com/FAForever/fa/blob/45ea30ea792135955f2021d613455ad9b2e7ea42/lua/sim/projectiles/aeon/AIMFlareProjectile.lua#L76)
This prevents the unit db for being accurate: any change in these files will cause the db to be outdated until someone notices it

It would be nice to have the deflected missile count and max radius written as constants or local variables more explicitly, so they can be somewhat reliably extracted from the file by the unit database