Fix TM moves for Beldum line

[jaimefd]

• Beldum also learns Tera Blast
• Metang also learns Giga Impact
• Metang does not learn Mud Slap, only Metagross (checked Gens 3-9)
• Metagross now learns Shadow Claw, Stone Edge and Knock Off in Gen 9
• Metang and Metagross now learn Trailblaze, Heavy Slam, Focus Punch and Future Sight in Gen 9

Beldum: https://bulbapedia.bulbagarden.net/wiki/Beldum_(Pokémon)#By_TM Metang: https://bulbapedia.bulbagarden.net/wiki/Metang_(Pokémon)#By_TM Metagross: https://bulbapedia.bulbagarden.net/wiki/Metagross_(Pokémon)#By_TM

Extra suggestion: I’d replace Psychic Fangs as an egg move since he learns it as TM (and Zen is a good replacement until you roll the TM). I’d put something like Close Combat/Headlong Rush in exchange. (Didn't change this, this is just an idea)