teach flywire_ids to accept any whitespace

[jefferis]

• also coconat keys (fw:xxx) but that can be a surprise for now

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 56.59%. Comparing base (1eabc55) to head (e8ad468). Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #198 +/- ## ======================================= Coverage 56.59% 56.59% ======================================= Files 38 38 Lines 4787 4787 ======================================= Hits 2709 2709 Misses 2078 2078 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.