text: Title: Remove full stop at end of viewer/layer action names
  Body: Related:  #7231(https://github.com/napari/napari/pull/7231#discussion_r1741406517)
  
  Some  viewer/layer action names end with a full stop and some do not, e.g.,
  
  https://github.com/napari/napari/blob/a9e7375e339a2240f6cc6affd05eceefa2e843e9/napari/components/_viewer_key_bindings.py#L200
  
  I propose that we remove the full stops which would make the names consistent and it would improve readability of error messages, e.g. the one in #7231
  
  If no objections will do this end of the week.