azure: add a tool to generate a billing report
It's a working POC generating the following reports for a one year range starting from the current day:
- Daily global cost + a graph
- Monthly global cost + a graph
- Per service daily cost
- Per service monthly cost
Related to swh/infra/sysadm-environment#4045 (closed)
We will need to find a place to run it somewhere in our private space
Migrated from D7356 (view on Phabricator)