Add Rage Fist

MR Description

• Adds the Rage Fist method (called s_rage_fist in Studio)

Before testing

• Affect the method s_rage_fist to a move in Studio

Tests to realize: (all of the above)

• The move increases in power by 50 every time the Pokémon knowing Rage Fist is hit.
• Only works for direct damage (no Stealth Rocks, Poison, Rocky Helmet etc).
• Base power is capped at 350.
• Isn't reset on switch, but is reset on a battle's end.
• Multi-hit moves strenghten the move for every hit landed.

Sources related to this MR

• Bulbapedia link
• Pokepedia link