Wii Fit Trainer cleanup/consistency

BUR #5389 has been approved by @evazion.

create alias wii_fit_trainer -> wii_fit_trainer_(female)
create alias male_trainer_(wii_fit) -> wii_fit_trainer_(male)

Consistency between the two genders of the character, similar to e.g., the Fire Emblem avatars (Robin, Corrin, Byleth).

Plan is to create BURs to remove the alias for the female trainer tag and then have both gender tags imply wii fit trainer, making it an umbrella tag.

The bulk update request #5389 (forum #185137) has been approved by @evazion.

BUR #5417 has been approved by @evazion.

remove alias wii_fit_trainer -> wii_fit_trainer_(female)
remove alias trainer_(wii_fit) -> wii_fit_trainer_(female)
create alias trainer_(wii_fit) -> wii_fit_trainer
create implication wii_fit_trainer_(female) -> wii_fit_trainer
create implication wii_fit_trainer_(male) -> wii_fit_trainer

As above.

The bulk update request #5417 (forum #185310) has been approved by @evazion.