ARCHBOM-1244: Add code_owner custom metric (#24084)

* includes ADR for Monitoring by Code Owner
* add monitoring middleware to add the following custom metrics:
- code_owner: The owning team mapped to the current view.
- code_owner_mapping_error: If there are any errors when trying to
        perform the mapping.
- view_func_module: The __module__ of the view_func, which can
        be used to find missing mappings.
* add script to generate `settings.CODE_OWNER_MAPPINGS` from
     a csv file.

ARCHBOM-1244