[gnome-software] (10 commits) ...Merge branch 'single-panel' into 'main'

[Philip Withnall <pwithnall src gnome org>]

Summary of changes:

  f2d8fe1... shell: Add a view switcher to the main header bar
  01379b4... shell: Add the is-narrow read-only property
  072a14a... shell: Stop using the sidebar
  d6d1a5f... shell: Use the app name as the main header title
  1941171... shell: Remove the now unused leaflets
  7aeb8e6... shell: Merge the title and content areas
  7f93808... shell: Rename search and menu buttons
  4c4aba4... shell: Fix the indentation
  8daae69... Drop GsSidebar
  670a1a4... Merge branch 'single-panel' into 'main'