allow manual Pokémon transforms in-between battle syncs

[doshidak]

Requested by: clawyf

Allow transforming Pokémon like Ditto to manually transform into another Pokémon in-between battle syncs. This should be enabled for any Pokémon with the Transform move or the Imposter ability.

As to not add further clutter to the UI, we can allow manual transformations through the existing forme switcher tooltip when the Pokémon's name is clicked on. Transformable Pokémon would include all Pokémon of other players (on second thought, might be a big tooltip, especially in FFA lol).

Lots of testing will be required to make sure manual transformations don't break existing fixes across ALL gens.