[FR]: Fail gracefully if coins file is invalid.

[smk762]

related: #2035

Is your feature request related to a problem? Please describe.
Currently if coins file is corrupt or has unexpected structure, app will fail to launch.

Describe your solution
We should be able to detect this, and if there is an issue, download the latest pinned coins data from the coins repo.

Describe alternatives you've considered
Alternatively we can output console logs and a "login failed - coins file invalid" modal which allows user to click button to reset coins.

Additional context
This happens sometimes during testing when we switch branches using different coins repo files which may include new fields for new methods or integrations.