luci-theme-material: overview boxes and buttons

luci-theme-material: overview boxes and buttons

Change mouse icon from text
cursor to pointer. Fix buttons not
being same min-width. Create
larger buttons for smaller screens,
same behaviour as
luci-theme-bootstrap. Slightly
fade "show" button: no variable
for disabled opacity like
luci-theme-bootstrap, assuming
0.7. Remove fade when hovered.

Resolve mismatched spacing for
each heading in box, fixing
spacing for when contents are
hidden and adding spacing
when contents are shown.

Signed-off-by: Joshua Criss <redacted>