Rename media files corresponding to their order value

[solth]

This PR adds a button to the metadata editor allowing users to rename all media files of the process according to the corresponding physical divisions ORDER attribute.

The new filename will be padded with 0 on the left to reach a filename length that can be configured for each project in the project settings.

The button is only displayed when the current user has the (new) permission to rename media files, which is not assigned to any role by default.

After renaming the media files has finished, a result dialog will be displayed, showing the number of files renamed in all configured process folders.

Filename changes will be reverted if the user does not explicitely save changes in the metadata editor. This approach is consistent with other functionalities in the editlor like uploading or removing images, which will also be reverted when leaving the metadata editor without clicking the "Save" button.

Fixes #5601

[markusweigelt]

Code looks good and it works for me!

Suggestions:

• Handling of error if number of filename length in project is too low for all images
• A test for resetting the media names when user not save changes after media renaming.

How do you do this?
After media renaming i restarted the application. All images where found but the meta.xml doesn't changed. How do you save the current state?

[markusweigelt]

I approved the PR last week, but I am still struggling with the scenario where the media is renamed and not saved, or the preDestroy method is not executed due to errors from the server and/or client side.

However, I was unable to produce such an problem during my tests by stopping the server immediately after the replacement. Therefore, I will maintain the approval from my side.

[solth]

• Handling of error if number of filename length in project is too low for all images

This is indeed not required as the StringUtils library I used only pads the filename with zeroes if required. If the name is already longer than target length passed to the padding method, it will not be altered and work just with the original filename.