Improve presentation of submission file revision history

[asmecher]

When a submission file is revised, those actions are tracked in a machine-readable way -- but in order to see the history of a file, the editor has to use the submission event log, which is not presented in a very friendly manner.

Consider ways to present the file revision history in more friendly ways. For example:

• Perhaps a more visual representation can be opened that is associated with the submission file's presentation, rather than the entire submission?
• Perhaps a reflection of the revision should be added back to the submission file list. (Previously -- perhaps 3.2 and older -- file IDs were presented as a mix of id-revision, e.g. 36-2 to indicate the 2nd revision of file ID 36.)

In addition to revisions within the current stage (submission_file_revisions table), we also track the source file ID (source_submission_file_id in the submission_file table). Both sets of data should be considered for presentation.