Added method to find all Datasets linked to a certain image
Added Multiple-Dataset warning dialog #11883

When the user wants to delete an image which is linked to multiple datasets a warning dialog will be shown, see trac #11883
Added empty method to NullOmeroPojoService to match OmeroDataService interface
Added comment, updated copyright date
Corrected copyright date
Warning dialog now shows information about the linked Datasets
Removed thumbnails from multiple dataset links warning dialog
Changed to a more performant database query
merge develop -D org: PR 2160 (Warning dialog before deletion of linked images)
merge develop -D org: PR 2165 (Inplace file path)
merge develop -D org: PR 2182 (Read only flag)
merge develop -D org: PR 2188 (Close the RFS and kill the root session.)
merge develop -D org: PR 2207 (Implemented maximum file size limit for import)
merge develop -D org: PR 2235 (customizing 'Orphaned images' container)
merge develop -D org: PR 2240 (Search image id 12151)
merge develop -D org: PR 2248 (Update develop submodules)
merge develop -D org: PR 2253 (limit webtest getObjects() to 10)
merge develop -D org: PR 2256 (Tablet drag handling)
merge develop -D org: PR 2258 (Truncate js tree dynamically 12161)
merge develop -D org: PR 2261 (Remove duplicate setting of uint16 bit size)