Minor UI changes to toolbar, added Cambalache file

Redesigned the bottom toolbar panel in the player
Minor XML and cosmetic changes in the .ui file
Added Cambalache file with links to the .ui file and .css file for
easier editing

Author: RobusTetus

data/net.base_art.Glide.cmb

@@ -0,0 +1,9 @@
+<?xml version='1.0' encoding='UTF-8' standalone='no'?>
+<!DOCTYPE cambalache-project SYSTEM "cambalache-project.dtd">
+<!-- Created with Cambalache 0.96.1 -->
+<cambalache-project version="0.96.0" target_tk="gtk-4.0">
+  <css filename="custom-style.css"/>
+  <ui filename="net.base_art.Glide.ui" sha256="f88dc410961be9c3ae74a94d5d5625e16c6bd34bdea497b289eb3ef993bf3994">
+    <css-provider>custom-style.css</css-provider>
+  </ui>
+</cambalache-project>