Add Opportunist

MR Description

• Adds the ability Opportunist. (Espathra's signature ability)

Before testing

• Add Opportunist (db_symbol: :opportunist) to your Studio database.

Notes to acknowledge before testing

• Mustn't activate if the stat boost is caused by Opportunist.
• If multiple stat raises occur of the same stat (Torch Song + Throat Spray => +2 SpA), it should be summed and copied afterwards. This does not work for this mr. Screw you, Game Freak.

Tests to realize

• Try raising a stat, Opportunist should activate and copy the stat raised.

Sources related to this MR

• Bulbapedia link
• Pokepedia link
• Discord link of the dev topic
• ClickUp link of the ticket