[RHELC-1055] Change the default message of an empty report message field

[hosekadam]

Based on conversation with Marek Hulan from Satellite in which he will be showing to the user the text form of the pre-conversion analysis report, we decided to change the default message from [No further information given] to N/A.

This is how a text report looked like before this change - report.txt - not that easy to read because of the many [No further information given] messages.

What do you think about this change, @mportman12 ?

Jira Issues: RHELC-1055

Checklist

• PR has been tested manually in a VM (either author or reviewer)
• Jira issue has been made public if possible
• [RHELC-] is part of the PR title
• GitHub label has been added to help with Release notes
• PR title explains the change from the user's point of view
• Code and tests are documented properly
• The commits are squashed to as few commits as possible (without losing data)
• When merged: Jira issue has been updated to Release Pending if relevant

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (f67fc2b) 93.92% compared to head (ad98300) 93.92%.
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #945   +/-   ##
=======================================
  Coverage   93.92%   93.92%           
=======================================
  Files          41       41           
  Lines        4147     4147           
  Branches      739      739           
=======================================
  Hits         3895     3895           
  Misses        179      179           
  Partials       73       73           

Flag	Coverage Δ
centos-linux-7	89.29% <100.00%> (ø)
centos-linux-8	89.87% <100.00%> (ø)

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Files	Coverage Δ
convert2rhel/actions/__init__.py	98.09% <100.00%> (ø)
convert2rhel/actions/report.py	100.00% <ø> (ø)

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[has-bot]

This PR does not require integration tests to be run.

---

@oamg/conversions-qe please review results and provide ack.

Log | Bot Usage

[r0x0d]

Looks good!

[mportman12]

LGTM