Time `<select>` issues

[Malvoz]

The issues can be seen/reproduced in debug/select-test.html or https://maps4html.org/experiments/datacube/

1. Can't change options in <select> using a mouse pointer
2. <label> within <summary> eats the pointer events so it's hard to toggle <details> to view <select> (must press the tiny "disclosure triangle")
3. HTML anatomy not consistent with opacity / style controls:
   
   

   <details class="mapml-control-layers"> <!-- opacity -->
     ...
   </details>
   <details class="mapml-control-layers"> <!-- style -->
     ...
   </details>
   <fieldset> <!-- time -->
     <details class="mapml-control-layers">
       ...
     </details>
   </fieldset>

[prushforth]

Would you say this is a result of #263, in general?

[Malvoz]

1. Can't change options in <select> using a mouse pointer

This is a result of only expecting <input> controls when implementing drag and drop of layers.

2. <label> within <summary> [...]

Is generally problematic and should indeed be fixed per #263.

3. HTML anatomy not consistent with opacity / style controls

A design choice really, but the "extra" <fieldset> I think is unnecessary and its semantics are not exposed to ATs unless the element is properly labelled anyway (e.g. using <legend> or aria-label(ledby)="").