[gnome-calculator] (16 commits) ...Merge branch 'master' into wip-gtk4-port

[Robert Roth <robertroth src gnome org>]

Summary of changes:

  2a38be7... Use eventcontroller for keyboard handling (*)
  4b560d7... Removed unused method (*)
  6c1d9ab... Converted function popover to use ListStore (*)
  13f09c9... Fixed typo (*)
  b17971d... Ported function popover to use bound model (*)
  0079f03... Refactoring model building out of the popover (*)
  68e2610... Use focus event instead of click event on function popover (*)
  d3a33a3... Use MathPopover as base for MathFunctionPopover (*)
  861ccb3... Use MathPopover as base for MathFunctionPopover (*)
  1d12f5f... Use changed listener instead of key listener for variable p (*)
  9614b82... VariablePopover uses the MathPopover class (*)
  b1b9ca8... More refactoring of common popover code (*)
  de43979... More preparations for Gtk4 with compatible calls (*)
  28d9171... Renamed function equals and compare methods (*)
  a75809c... Use GtkBox instead of HBox and VBox (*)
  1e25b9a... Merge branch 'master' into wip-gtk4-port (*)

(*) This commit already existed in another branch; no separate mail sent