Debug logging for expired SPA and store refresh token

[thijs-nijhuis]

Resolves #640

Description

When using an Azure App Registration with a 'Single-page Application' authentication platform as the oAuth endpoint, the token will always expire after 24h. It is not possible to fetch a new token after this and a new consent (and external browser login) is required. This is 'by design' and should therefore not yield warning in the terminal hinting on a possible problem. Instead, writing to the debugger should suffice. The second issue this PR tackles is that, after a token expires and a new refresh token is requested from the endpoint, that new token is never stored. This causes the authentication logic to request a new refresh token for every dbt command after initial token has expired (valid for 1h) where it is only needed after it is expired.

Checklist

• [x] I have run this code in development and it appears to resolve the stated issue
• [x] This PR includes tests, or tests are not required/relevant for this PR
• [ ] I have updated the CHANGELOG.md and added information about my change to the "dbt-databricks next" section.

[benc-db]

Re-pushing to run integration tests.

Can you run

tox -e linter

to see what you need to fix linting issue?

[thijs-nijhuis]

@benc-db , sorry about that. Forgot about the linter. I ran it and it fixed a couple of things. I also changed the code slightly to check if the token has changed after it is checked to be valid. Only when changed, it will store the new token using keyring

[benc-db]

Going to open a new PR of this to update the changelog and then merge. Thanks for the contribution!

[benc-db]

Closed in favor of 700.