Enh/image suggestions - #701

This branch bring the photo location suggestions to vue. (Previously called nonlocalized photos.)
This PR contains only the fronted part, which works quite nicely and it requires #700.

The Implemented Workflow:

1. The user can load photo location suggestions from the Actions in the photos app Navigation Menu
2. Images are shown on the map and the sidebar opens.
   • If no suggestions are received from the backend there is an information in the sidebar
3. The user selects suggestions by clicking on the image shown on the map.
   • If no suggestion is selected there is a information in the sidebar, that suggestions can be selected by clicking them on the map
   • There is a select all button
   • A clear selection button
   • A a cancel button
   • A save button
4. Clicking the save button will store the suggested location into the selected images.

To test this branch you have to make the back-end deliver photo-suggestions. While this should work principle, it has many cases, where it just doesn't work. To test the branch I patched the PhotoController.php locally to provide dummy data.

     /**
     * @NoAdminRequired
     * @NoCSRFRequired
     */
    public function getNonLocalizedPhotosFromDb() {
        $result = $this->geophotoService->getNonLocalizedFromDB($this->userId);
	//Get Suggestions for Development fix real suggestions later
	$result = $this->geophotoService->getAllFromDB($this->userId);
	foreach ($result as $r) {
		$r->lat = $r->lat + 0.1;
		$r->lng = $r->lng + 0.1;
	}
        return new DataResponse($result);
    }

Changes which improve the backend are in:

• Bootstrap: Migrated to App Bootstrap #703
• Scan now: Added Option to scan photos now #704
• Exif handling: Image handling backend #705

To test this PR with backend improvements checkout enh/image-suggestions-with-backend.