Problem: combining PREMIS files no longer required

[sallain]

Describe the issue

The client has decided to leave the PREMIS files located in the content directory as-is. The following features will need to be removed:

• [x] Combine premis.xml files from content directory into a single premis.xml file
• [x] Delete premis.xml files from content directory

The original description of the work included two move tasks - placing Prozess_Digitalisierung_PREMIS.xml and UpdatedAreldaMetadata.xml in the metadata directory. These moves can remain.

[fiver-watson]

Confirmed that PREMIS files are no longer combined in most recent tests