Initial solution for 9171

 + Make dt_dev_jump_image callable from outside of darkroom.c
 + Use this function in filmstrip.c to move to the next image when
   one image is rejected.
Implement a more generic solution in view.c
Make the filmstrip to scroll to the image being loaded in darkroom
Make sure that the mouse_over_id var holds a valid imgid

 + When an image is rejected, the imgid of it is not valid, making
 _metadata_view_update_values in metadata_view.c fail. This patch makes
 sure the variable is set to the new image being loaded in any case.
Jump to the next image both when the image is rejected using the mouse or key accel
Select the next image in filmstrip if the current one disappears from collection

 If the current image being worked on is rated in the filmstrip in a different
 level, it may disappear from the current filtered collection. If that happens,
 the next image in the filmstrip will be selected and activated.
 Fixes #9171
Merge branch 'fix-9171'