Add old "Breeze" Task Switcher here under the new name "Sidebar"
Since it's now been taken out of the Breeze Global Theme, which was a bit of an odd place for it, let's move it here so people who liked it can continue to use it.
This commit includes the code taken verbatim from kdeplasma-addons as of commit a4ec95fb8edecab693c26ccd130fa3e99b62322b.
Edited by Nate Graham