Made users header interface more adaptable

Search input was stacking on create button on default desktop view
due when viewing in russian due to combined width exceeding container.
Made into normal flexbox instead.

Closes #2147

resources/sass/_layout.scss

@@ -157,6 +157,9 @@ body.flexbox {
 .justify-center {
   justify-content: center;
 }
+.justify-space-between {
+  justify-content: space-between;
+}
 .items-center {
   align-items: center;
 }