Fix inconsistencies between CamelCase and ALL_CAPS in log lines

We seem to be outputting both ArchiveForUser and ARCHIVE_FOR_USER in the logs. It should be only one of these; specifically, ArchiveForUser.

The current list of known inconsistencies is:

• ArchiveForUser vs ARCHIVE_FOR_USER
• ArchiveForRepack vs ARCHIVE_FOR_REPACK
• Retrieve vs RETRIEVE

This seems to be a result of the toString method in MountType.cpp. The easiest solution to this is replace the implementation of toString here with the implementation of toCamelCaseString and then remove the toCamelCaseString method.

What should be inspected is whether this change would affect anything else.