feat(data/equiv/basic): equiv.curry (#7458)
This renames `equiv.arrow_arrow_equiv_prod_arrow` to `(equiv.curry _ _ _).symm` to make it easier to find and match `function.curry`.
* `cardinal.power_mul` is swapped, so that its name makes sense.
* renames `linear_equiv.uncurry` to `linear_equiv.curry` and swaps sides
Also add `@[simps]` to two equivs.
