As a follow up to the technical preview of the pre-conversion analysis feature (RHELC-751), this Epic will focus on its improvements necessary for the MVP integration with Insights (HMS-1768). Namely, the report shall be generated in a machine-readable format.

Acceptance criteria:

• convert2rhel exits with various codes hinting why the tool has stopped (successful conversion, python traceback, warning/inhibitor in the pre-conversion report, error in the post-conversion report, etc.)
• The report is generated in a machine readable format (JSON)
  • The report should have similar format as the `leapp preupgrade` report. That way it would not be a problem when moving convert2rhel over to the leapp framework.
  • The report is structured in a way that it may later include not only the failure message but also a suggested remediation that could be machine-readable and executable (similarly to how Leapp has it).
• There's a new convert2rhel sub-command to execute the pre-conversion analysis only, e.g. `convert2rhel analyze`
• The report includes not only problems preventing the system from proceeding with conversion (inhibitors), but also warnings