Centralize changing the operation mode in operation_mode_set()
Centralize changing the operation mode in operation_mode_set()

This will be the central function to switch operation modes:  stop searches or the recent-files
process; switch widgets, etc.

We factor out the common code from recent_switch_to_browse_mode() and search_switch_to_browse_mode(),
and remove those functions.  All the code that switched modes by hand now calls
the central operation_mode_set().

Signed-off-by: Federico Mena Quintero <4999915a961edfd7686112c2935288e1266eae14@gnome.org>

alexlarsson/gtk,Sidnioulz/SandboxGtk,ebassi/gtk,ahodesuka/gtk,chergert/gtk,jadahl/gtk,Lyude/gtk-,chergert/gtk,bratsche/gtk-,Lyude/gtk-,davidt/gtk,alexlarsson/gtk,davidgumberg/gtk,jessevdk/gtk,Adamovskiy/gtk,msteinert/gtk,jessevdk/gtk,msteinert/gtk,grubersjoe/adwaita,davidt/gtk,Adamovskiy/gtk,ahodesuka/gtk,jigpu/gtk,jessevdk/gtk,ahodesuka/gtk,Distrotech/gtk2,ebassi/gtk,Lyude/gtk-,jadahl/gtk,davidgumberg/gtk,jigpu/gtk,Lyude/gtk-,Adamovskiy/gtk,ebassi/gtk,jigpu/gtk,Distrotech/gtk2,ebassi/gtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,jadahl/gtk,grubersjoe/adwaita,Distrotech/gtk2,grubersjoe/adwaita,ahodesuka/gtk,jigpu/gtk,grubersjoe/adwaita,Lyude/gtk-,Adamovskiy/gtk,grubersjoe/adwaita,Distrotech/gtk2,jadahl/gtk,davidt/gtk,grubersjoe/adwaita,alexlarsson/gtk,jessevdk/gtk,Sidnioulz/SandboxGtk,msteinert/gtk,alexlarsson/gtk,jessevdk/gtk,chergert/gtk,jigpu/gtk,chergert/gtk,bratsche/gtk-,davidt/gtk,davidgumberg/gtk,ahodesuka/gtk,jigpu/gtk,bratsche/gtk-,Adamovskiy/gtk,jigpu/gtk,msteinert/gtk,jessevdk/gtk,alexlarsson/gtk,jadahl/gtk,Lyude/gtk-,chergert/gtk,jessevdk/gtk,Sidnioulz/SandboxGtk,Distrotech/gtk2,jadahl/gtk,chergert/gtk,Sidnioulz/SandboxGtk,jadahl/gtk,Lyude/gtk-,alexlarsson/gtk,alexlarsson/gtk,ahodesuka/gtk,ahodesuka/gtk,grubersjoe/adwaita,davidgumberg/gtk,bratsche/gtk-,davidgumberg/gtk,grubersjoe/adwaita,msteinert/gtk,chergert/gtk,alexlarsson/gtk,ahodesuka/gtk,ebassi/gtk,davidt/gtk,davidgumberg/gtk,Adamovskiy/gtk,chergert/gtk,bratsche/gtk-,bratsche/gtk-,Sidnioulz/SandboxGtk,davidgumberg/gtk,ebassi/gtk,Adamovskiy/gtk,Adamovskiy/gtk,jadahl/gtk,davidt/gtk,Lyude/gtk-,msteinert/gtk,jigpu/gtk,Distrotech/gtk2