GHAE support (on-hold)

[ArinGhazarian]

Closes #375

This PR adds the --target-api-url to all gh gei commands for GitHub to GitHub migration paths.

• [x] Did you write/update appropriate tests
• [x] Release notes updated (if appropriate)
• [x] Appropriate logging output
• [x] Issue linked
• [x] Docs updated (or issue created)

[github-actions[bot]]

Integration Test Results

4 tests  ±0   4 :heavy_check_mark: ±0   8m 11s :stopwatch: - 1m 16s 1 suites ±0   0 :zzz: ±0  1 files   ±0   0 :x: ±0 

Results for commit b9f00749. ± Comparison against base commit 4ff6be01.

:recycle: This comment has been updated with latest results.

[github-actions[bot]]

Unit Test Results

523 tests   523 :heavy_check_mark:  31s :stopwatch:     1 suites      0 :zzz:     1 files        0 :x:

Results for commit a02ad5bc.

:recycle: This comment has been updated with latest results.

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
ado2gh	90%	85%	585	✔
Octoshift	92%	79%	519	✔
gei	89%	87%	420	✔
Summary	90% (4647 / 5144)	84% (1012 / 1210)	1524	✔

[dylan-smith]

Closing this as we're not likely to revive it at this point.