Enable custom span tags across all services to unblock upgrade observability

[robrap]

The Python/Django version dashboard in DD in not functional for all services, until this migration sheet for APM: Django Version is completed. The sheet contains instructions for completing this work.

It may be simpler for arbi-bom to implement this on the behalf of service owners, then to try to get all the service owners to resolve this.

While doing this work, there are several monitoring middleware renames (paths or names) that it would be nice to clean-up at the same time. See https://github.com/search?q=repo%3Aopenedx%2Fedx-django-utils%20deprecated_monitoring_middleware&type=code. The instructions in the spreadsheet may search for older names only.

[robrap]

• I recommend you merge, deploy, and inform for each service.
  • If the deployment of another service would involve deploying additional changes, skip the deployment step and simply merge and inform.