feat(a11y): explicitly associate label and input elements

[pano9000]

Hi,

this PR ads an explicitly associated label to input elements that did not have one previously (I hope I found all of them :-))

This closes #790.

In a separate PR I will continue working on turning the implicit labels into explicits ones as well, as they usually seem to work better with screen readers, from what I've read online.

[eliandoran]

Looks good for me for now.

Indeed, wrapping the <input> inside the <label> would actually work better because I think the current implementation does not work well when you have multiple tabs of the same view (i.e. options), since you have the same ID multiple times in the hierarchy.

[pano9000]

Indeed, wrapping the <input> inside the <label>

that would actually be an implicitly associated label again, which I would want to avoid.
The id issue is potentially valid comment though, I will need to do some tests with it

[pano9000]

I just did a quick test and and can confirm, if you open up two of the same widgets (like with the Options), there will be two identical ids - which can cause unexpected behaviour (i.e. the focus jumps to the "first" element with that id, which might not be your active tab)

I'll create a bug ticket this evening and work on getting this fixed