improve horizontal menu positions for RTL

bigbluebutton-html5/imports/ui/components/dropdown/styles.scss

@@ -11,6 +11,7 @@
   --dropdown-caret-height: 8px;
 
   --rtl-caret-offset: -0.4375rem;
+  --rtl-content-offset: 11.3rem;
 }
 
 .dropdown {
@@ -32,6 +33,10 @@
   border: 0;
   padding: calc(var(--line-height-computed) / 2);
 
+  [dir="rtl"] & {
+    right: var(--rtl-content-offset);
+  }
+
   &:after,
   &:before {
     content: '';

bigbluebutton-html5/imports/ui/components/user-list/user-list-content/user-participants/user-options/styles.scss

@@ -23,6 +23,11 @@
   left: auto;
   width: var(--user-manage-menu-width);
 
+  [dir="rtl"] & {
+    top: var(--user-manage-menu-top);
+    right: -1rem;
+  }
+
   @include mq($small-only) {
     width: 100vw;
   }