Relax vanilla weapon switching restrictions in casual play

[ceski-1]

Related issue: https://www.doomworld.com/forum/topic/112333-this-is-woof-1530-nov-03-2025/?page=114&tab=comments#comment-2994052

If a player is using vanilla complevel but is not in strict mode, nor demo recording, nor in a netgame (e.g. casual play only), we should allow them to change these settings:

There may be an issue of balancing author intent vs. user friendliness. I'm guessing there are wads out there made with the vanilla restrictions in mind (either a gimmick or a dehacked trick).