Adjust topbar (first pass)

- Change the collapse/expand icon;
- remove old unnecessary CSS rules (adjust buttons height)
- add space (gap) between top menu items

Signed-off-by: RD WebDesign <github@rdwebdesign.com.br>

scripts/lua/header_authenticated.lp

@@ -43,7 +43,7 @@ mg.include('header.lp','r')
         <ul class="navbar-nav">
             <li class="nav-item">
                 <a class="nav-link" data-widget="pushmenu" href="#" role="button" aria-label="Toggle Navigation">
-                    <i class="fa fa-bars"></i>
+                    <i class="fa fa-angle-double-left"></i>
                     <span class="warning-count badge navbar-badge hidden" id="top-warning-count"></span>
                 </a>
             </li>

style/pi-hole.css

@@ -896,14 +896,9 @@ body:not([class*="lcars"])
 }
 
 .navbar-nav {
-  height: 50px;
+  gap: 1em;
 }
 
-.navbar-nav > .user-menu {
-  margin-left: 15px;
-  width: 50px;
-  text-align: center;
-}
 @media screen and (min-width: 767px) {
   .navbar-nav > .user-menu {
     background: rgba(0, 0, 0, 0.1);
@@ -1497,10 +1492,6 @@ table.dataTable tbody > tr > .selected {
   padding-top: 1rem !important;
 }
 
-.d-none {
-  display: none !important;
-}
-
 .password_background {
   background-image: repeating-linear-gradient(
     45deg,