This commit gives a small refresh to the web_editor UI. To do so we
remove the borders from the buttons and inputs. We also increase the
border radius to 4px instead of 2px. The nested menus such as in Themes
tab now have the same background color than the rest of the UI.
The box shadows on the `we-title`, `we-customize-block-options` and the
checkbox switch have been removed.
All the buttons and select components are now taking the full available
width. The inputs fields remain unchanged except their font which is now
set to sans-serif.
Finally a `<div>` have been added to the replace media snippet to make
it consistent with the other buttons having an icon. Maybe in the future
we'll need a better way to define those.
task-3265187
closesodoo/odoo#119697
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>