Stop timers in various widgets on unmap
See the commit messages for details. This essentially applies the same changes to the following widgets, which all have repeating background timers to update the UI in some form:
GsFeaturedCarousel
GsLoadingPage
GsUpdatesPage
GsUpgradeBanner
If we keep those timers running while unmapped, they’re updating a UI which isn’t visible, which is a pointless reason to wake up the gnome-software
process.
Closes #2640 (closed)
Edited by Philip Withnall