Add migration scripts from RHOAI 2.x to RHOAI 3.x

[CathalOConnorRH]

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What changes have been made

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• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • Testing is not required for this change

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.97%. Comparing base (e3aecbb) to head (5eb75d5).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #964   +/-   ##
=======================================
  Coverage   95.97%   95.97%           
=======================================
  Files          23       23           
  Lines        2211     2211           
=======================================
  Hits         2122     2122           
  Misses         89       89           

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[chipspeak]

LGTM barring the two suggestions (which might be overkill).

[chipspeak]

CI is just failing as GitHub is having issues today I think but might be worth a re-trigger in any case.

[kryanbeane]

couple of points / questions

[pawelpaszki]

executed the script with the most simple commands (pre-upgrade and post-upgrade) without any flags on 2.25 -> 3.3 (nightly). all good

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pawelpaszki

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