chore: add KeptnApp migration script

[RealAnna]

added basic conversion code to generate app context from an old keptn app

https://github.com/keptn/lifecycle-toolkit/tree/main/lifecycle-operator/converter is added in this pr so the
link checks fail

[codecov]

Codecov Report

Attention: 19 lines in your changes are missing coverage. Please review.

Comparison is base (45a56d1) 87.14% compared to head (a19dc57) 85.85%.
Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2959      +/-   ##
==========================================
- Coverage   87.14%   85.85%   -1.29%     
==========================================
  Files         107      162      +55     
  Lines        6767    10335    +3568     
==========================================
+ Hits         5897     8873    +2976     
- Misses        719     1174     +455     
- Partials      151      288     +137     

Files	Coverage Δ
lifecycle-operator/converter/convert_app.go	75.32% <75.32%> (ø)

... and 54 files with indirect coverage changes

Flag	Coverage Δ
certificate-operator	67.42% <ø> (?)
component-tests	55.80% <ø> (ø)
lifecycle-operator	85.49% <75.32%> (-0.13%)	⬇️
metrics-operator	87.63% <ø> (?)
scheduler	36.53% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[StackScribe]

Approving the docs. I left a couple little suggestions for you to consider.
And yeah, probably not the most essential tool ever but it does prevent a lot of careless copy/paste errors so why not?

[mowies]

please add the converter folder to the make unit-test command

[sonarqubecloud]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

done