Transactions cleanup

[dogversioning]

This PR makes the following changes:

• Removes template study uploads, just moving the file to archives (Discard data uploaded from template study #100)
• Fixes one instance of a different key name for last_update causing multiple last update keys in transaction data
• fixes spelling of transaction_format_version
• Provides a migration script to apply these changes in different environments

[mikix]

Honest question: why this line? Why not migrate unexpected uploaders? And/or, maybe flag / warn about unexpected site uploads - that seems like a big surprise.

[dogversioning]

so that's related to #101 (comment) - it is unexpected and it has happened, I think I IDed the root cause, and I'm trying to clean them up since we can't tie them back to a specific place and they make no sense in the aggregation tool i'm working on.

[mikix]

general testing comments:

• I would have expected to see some test changes for the last_upload key change - that code path must not be tested right now?
• Probably worth adding a test for the new template archiving

[dogversioning]

yeah fair point

[dogversioning]

Ok - a true headache, but i've at least got a check for this case (and this was wrong to begin with, not just in terms of typos but in terms of which element is was pointed at).

I'm putting coverage on my short list for this repo.

[mikix]

I forgot to approve - I think my only real suggestion was the "needs more tests" one anyway and looks like you've added some