Set default padding/margin to 0 for picker/switch

[BlueRaja]

Description

The majority of controls in MAUI have no padding/margin by default, which is great. However Picker, Switch, and probably others do. Even worse, these controls have no writable Padding property, meaning it's impossible to remove the excess whitespace without a native handler (and in fact I haven't been able to remove it even with a native handler).

Ideally Padding/Margin properties would be added to the MAUI controls. I assume this hasn't been done yet because it's too hard. Fine, whatever. But at the very least, please set the default padding/margin to 0. It's very easy to add padding to a control that doesn't support it, by surrounding it in a Box or something. But it's nearly impossible to remove padding from a control.

Public API Changes

n/a

Intended Use-Case

This would be useful for basically everyone

[bradencohen]

+1. Same for RadioButton. Had to swim very upstream to get that control to look like my others.