Summary:
- Replace logger module by the standard module 'logging'.
- When a log message from the sandbox includes newlines (e.g. for tracebacks),
keep those lines together in the Node log message.
Previously each line was a different message, making it difficult to view
tracebacks, particularly in prod where each line becomes a separate message
object.
- Fix assorted lint errors.
Test Plan: Added a test for the log-line splitting and escaping logic.
Reviewers: georgegevoian
Reviewed By: georgegevoian
Differential Revision: https://phab.getgrist.com/D3956
534615dd50