[TF2] Allow damaging taunts to respect friendly fire rules

[Professor-Heavy]

This aims to consolidate damaging taunts under friendly fire rules (mp_friendlyfire 1). Some taunts allow for friendly fire damage as they leave those checks to CTeamplayRules::FPlayerCanTakeDamage to decide, which performs the check as TakeDamage is being run. This explicitly removes the "same team" checks from the others, instead allowing the damage to be aborted during the appropriate checks rather than just refusing to check in the first place.

There are some wherein the ConVar checks are performed during the taunt attack code instead, just to prevent any side effects (Armageddon taunt taking additional targets into account for damage when friendly fire is off, stunning taunts, etc).

Relates to issue ValveSoftware/Source-1-Games#7903

The following are affected by this:

• TAUNTATK_SCOUT_GRAND_SLAM
• TAUNTATK_PYRO_ARMAGEDDON
• TAUNTATK_DEMOMAN_BARBARIAN_SWING
• TAUNTATK_ENGINEER_ARM_KILL and TAUNTATK_ENGINEER_ARM_BLEND
• TAUNTATK_MEDIC_UBERSLICE_IMPALE and TAUNTATK_MEDIC_UBERSLICE_KILL (Does not refill charge)
• TAUNTATK_ENGINEER_TRICKSHOT
• TAUNTATK_ENGINEER_GUITAR_SMASH
• TAUNTATK_SNIPER_ARROW_STAB_IMPALE and TAUNTATK_SNIPER_ARROW_STAB_KILL
• TAUNTATK_RPS_KILL