Improve inspect hover UI (#879)

Fixes #868
- #868

It solves all the block within blocks and all kind of controls that are
not required which creates gaps.
I use a simple table, so the width is dynamic but it is always aligned
for all the properties and the features.

![image](https://github.com/maplibre/maputnik/assets/3269297/75138b00-ec7b-4e8d-b51b-f8ff6abcd5cb)

Vary basic stuff.
There's still the layer popup, which I'm not sure I know what it is and
might need to be fixed as well.
CC: @zstadler

src/styles/_popup.scss

@@ -36,3 +36,12 @@
     margin-top: $margin-2;
   }
 }
+
+.maputnik-popup-table {
+  width: 100%;
+}
+
+.maputnik-popup-table-cell {
+  color: $color-lowgray;
+  padding-left: $margin-2;
+}