[TF] Fix regressions caused by recent Caber explosion change (with improvements)

[Bitl]

Description

This is an update to #1697, which I have closed because I felt like it would be good to completely redo the commit history and start from scratch. I also have decided to improve it with more features that would benefit modders, and bring in an important bug fix that bugged Caber users.

This PR fixes some minor regressions from the Caber explosion change introduced in #1456, which includes:

• Can now steal the PASS Time JACK.
• Can now destroy Sticky Bombs.
• Increased healing with Vampire powerup in Mannpower.
• Decreased damage with mini-crits in Mannpower.

To fix these, the Caber no longer uses DMG_MELEE explicitly. The changes are now checked amongst its existing TF_DMG_CUSTOM_STICKBOMB_EXPLOSION damage type, which brings the following changes:

• Can no longer steal the PASS Time JACK.
• The caber now properly pushes stickybombs with the force from the tf_grenade_forcefrom_blast value, but no longer breaks them as the Caber doesn't use DMG_IGNITE.
• Mannpower changes have been restored to previous settings.

This extended version of the PR also introduces the following changes:

• Improved formatting.
• Added support for the dmg_from_melee attribute, used by the Fists of Steel.
• Fixed the explosion damage not increasing with mini-crits.
• Further attribute support for the following attributes:
  • crit_does_no_damage
  • mult_dmg_bonus_while_half_dead
  • mult_dmg_penalty_while_half_alive
  • mult_dmg_with_reduced_health

There are no plans to introduce any reversions to the caber explosion using attributes (as mentioned in ValveSoftware/Source-1-Games#7738) as there is no definite proof of there being a change to the Caber's explosive radius and damage.

Closes ValveSoftware/Source-1-Games#4428.