update current user info during sync

[sssoleileraaa]

Description

Towards #76

Next step (after this PR): update gui auth widget to show updated name

Test Plan

1. log in
2. change first and last name of the account you're logged into from the admin UI
3. wait until next sync then check local client db
   • verify local db shows updated first and last name
4. change first and last name to empty string
5. wait until next sync then check local client db
   • verify local db shows updated first and last name
6. change first and last name from journalist UI (not admin UI)
7. wait until next sync then check local client db
   • verify local db shows updated first and last name
8. change username from admin UI (can't do this from journalist UI)
   • verify local db shows updated username

[sssoleileraaa]

It appears that adding the api.get_current_user call to the metadata sync job breaks functional tests in a somewhat mysterious way that has to with cassettes perhaps. If we need to generate new cassettes when we modify some parts of client code, we should document a) how to generate new cassettes, e.g. server setup - do we want NUM_SOURCES to be 5 or some other value, and b) in what cases do we need to generate new cassettes, e.g. adding a new api job or adding a new api call to the client.

(To be continued)

[sssoleileraaa]

After #1138 is merged, I can do a bit of conflict resolution, then tests should pass, and i'll move this from draft to ready-for-review.

[sssoleileraaa]

Now that #1138 has been merged, cassette generation in the client was a breeze~~ and this can be reviewed now.

[rmol]

All good:

1. log in
2. change first and last name of the account you're logged into from the admin UI
3. wait until next sync then check local client db
   • verify local db shows updated first and last name
4. change first and last name to empty string
5. wait until next sync then check local client db
   • verify local db shows updated first and last name
6. change first and last name from journalist UI (not admin UI)
7. wait until next sync then check local client db
   • verify local db shows updated first and last name
8. change username from admin UI (can't do this from journalist UI)
   • verify local db shows updated username

Looking at this, I'm starting to think storage.find_or_create_user and storage.update_and_get_user could be merged, but if so, it should be done in another change.