Rename files

[sssoleileraaa]

Description

Fixes #238

What changed?

securedrop_client/message_sync.py

• I think we log too often here. Since it is a debug log, I left 2 of the 4 logs inside the 5-second loop

securedrop_client/storage.py

• I made some opinions about log levels here
• New rename_file function
• update_submissions and update_replies now update data files to match new filenames in the db.

tests/conftest.py

- I added a data_dir pytest function. I plan to make a follow-up PR for a couple renaming refactors that would have made this PR harder to follow had I added them here. But basically I think we need to pass data_dir where we pass homedir in many test instances. Not a huge deal but it would be more correct to mimic what we do in production.

tests/test_storage.py

• Added some unit tests for the new rename_file function
• Updated existing tests: test_update_submissions and test_update_replies to check that rename_file is called if the local storage filenames need to be updated

---

Update:

• update_submissions and update_replies now update data files to match new filenames in the db.

The reply and submission files are renamed in these functions when we have both the local filename and server filename. This makes it easy to ensure local matches what's on the server.

Another option would be to rename the files in update_sources when the journalist_designation has changed. This would show the connection between a new journalist_designation and filename updates, but the code would be a bit more complicated because the filenames would need to be rebuilt, hard-coding the file naming structure so that we can find and replace the journalist_designation in the middle of the filename.

I went with the first option because it would require less maintenance if in the future we decide to change the way files are named or there ends up being more reasons that file names can become out of sync. This logic says "regardless of reason the names have changed, local should always match the server."

[sssoleileraaa]

Added additional test, signed and fixited commits.

[heartsucker]

One nit for code style, otherwise good to merge.