[Dark theme] Fix styles for context menus overlay

The context menus HTML structure changed and the dark theme CSS styles
no longer applied to them. This change fixes this.

Fixes: #33
Change-Id: I8773758d05660a0728e2858f982e0ff78e9a57f2
diff --git a/src/injections/ccdarktheme.css b/src/injections/ccdarktheme.css
index 5b37497..58c5689 100644
--- a/src/injections/ccdarktheme.css
+++ b/src/injections/ccdarktheme.css
@@ -80,11 +80,12 @@
 /*
  * This applies not only to the selector but also to the ec-work-state-picker.
  */
-.popup-wrapper, material-list {
+.popup-wrapper, material-list, .popup .item-group-list {
   background-color: var(--TWPT-drawer-background)!important;
 }
 
-material-list [group]:not(.empty) + *:not(script):not(template):not(.empty) {
+material-list [group]:not(.empty) + *:not(script):not(template):not(.empty),
+    .popup .item-group-list [group]:not(.empty) + *:not(script):not(template):not(.empty) {
   box-shadow: inset 0 8px 0 0 var(--TWPT-drawer-background)!important;
   border-top-color: #1f1f1f!important;
 }
@@ -94,14 +95,29 @@
     material-list material-select-dropdown-item:hover,
     material-list material-select-dropdown-item:focus,
     material-list material-select-dropdown-item.active,
-    material-list material-select-dropdown-item:not(.multiselect).selected {
+    material-list material-select-dropdown-item:not(.multiselect).selected,
+    .popup .item-group-list material-select-item:hover,
+    .popup .item-group-list material-select-item:focus,
+    .popup .item-group-list material-select-dropdown-item:hover,
+    .popup .item-group-list material-select-dropdown-item:focus,
+    .popup .item-group-list material-select-dropdown-item.active,
+    .popup .item-group-list material-select-dropdown-item:not(.multiselect).selected {
   background-color: rgba(255, 255, 255, .04)!important;
 }
 
-material-list .menu-item-label, material-list .label, material-list .text-segment {
+material-list .menu-item-label,
+    material-list .label,
+    material-list .text-segment,
+    .popup .item-group-list .menu-item-label,
+    .popup .item-group-list .label,
+    .popup .item-group-list .text-segment {
   color: rgba(255, 255, 255, .87)!important;
 }
 
+.popup .item-group-list material-icon {
+  color: rgba(255, 255, 255, .7)!important;
+}
+
 material-list [group] > [label] {
   color: #8a8a8a!important;
 }