Button and Form Element Size Normalization

[endigo9740]

This will include:

• Ensure buttons and form inputs have a normalized height
• Reviews options to offer multiple size inputs (which match button sizes)
• (more requests welcome below)

[DevOfManyThings]

As mentioned on discord, I think it makes sense to consistently apply the rounded-container attribute to form inputs.
The below example is about textareas, but I think it should really apply to all form input elements as it makes everything consistent and just better looking imo.

For textareas in particular it avoids the below example for themes with rounded elements cutting off visible text for larger text areas, and imo just looks more consistent that way.

[endigo9740]

Resolved by #3189