Support form labels for all form elements

[maxatdetroit]

The Problem

Our checkboxes and radio buttons support setting labels using an element attribute, however our input and select elements do not. Additionally, all form elements should support setting labels using slots to enable custom markup if needed.

The Solution

• Add a label attribute and slot to our input and select elements.
• Update our checkboxes and radio buttons to support a label slot (in addition to the existing label attribute).

[maxatdetroit]

On second thought, we'll leave the label elements coupled with their respective form control in the design system. This seems to be a common paradigm in other popular design system and removes the burden on the design system user to correctly associate the label to the form element.

E.g. https://shoelace.style/components/input/

[maxatdetroit]

Well, now that I'm looking at the design system, it looks like we're not consistent in how we approach labels. So this issue will be to bring consistency to our labels and form elements.