♿️(frontend) set focus style globally

Lot of elements did not have a focus style, or the
focus style was not consistent. We now have a global focus
style that is applied to all elements that are
focusable. The style is still overridable for
specific elements, so buttons and other elements
still have their own focus style.
We will have probably to improve the focus style
in the future of some elements, but this is a
good start.

src/frontend/apps/impress/src/pages/globals.css

@@ -24,6 +24,12 @@ body > #__next > .c__app > div:has(> .c__loader) {
   box-sizing: border-box;
 }
 
+*:focus-visible {
+  outline: 2px solid var(--c--globals--colors--brand-400);
+  outline-offset: calc(-1 * var(--c--globals--spacings--4xs));
+  border-radius: var(--c--globals--spacings--2xs);
+}
+
 main ::-webkit-scrollbar,
 .ReactModalPortal ::-webkit-scrollbar {
   width: 20px;