XWIKI-22133: The upper part of the Drawer is missing on smaller mobile screens

* Use 100dvh as height instead of 100vh to make sure that the drawer is
  fully visible when the viewport is resized, e.g., due to the
  navigation bar. Use 100vh as fallback as dvh is still relatively new.

(cherry picked from commit 3aa2f06a)

xwiki-platform-core/xwiki-platform-flamingo/xwiki-platform-flamingo-skin/xwiki-platform-flamingo-skin-resources/src/main/resources/flamingo/less/drawer.less

@@ -31,14 +31,18 @@
   width: @xwiki-drawer-width;
   right: 0;
   overflow: hidden;
+  // Fallback for browsers that don't support dvh.
   height: 100vh;
+  height: 100dvh;
   margin-right: -@xwiki-drawer-width;
   transition: margin-right .6s cubic-bezier(0.190, 1.000, 0.220, 1.000);
   padding: 0;
   border: 0;
   overflow-y: auto;
   // We overwrite max-height over browser defaults for dialog
+  // Fallback for browsers that don't support dvh.
   max-height: 100vh;
+  max-height: 100dvh;
   
   &::backdrop {
     opacity: 0;