Add repo visibility to migrate-repo commands

[tambling]

This PR adds the first half of https://github.com/github/gh-gei/issues/5: adding --target-repo-visibility to our migrate-repo commands, which will then send that setting up to the monolith's StartRepositoryMigration mutation (which handles the rest).

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

[github-actions[bot]]

Integration Test Results

4 tests  ±0   4 :heavy_check_mark: ±0   18m 43s :stopwatch: + 3m 50s 1 suites ±0   0 :zzz: ±0  1 files   ±0   0 :x: ±0 

Results for commit f87c4b30. ± Comparison against base commit 9a6894fc.

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

[github-actions[bot]]

Unit Test Results

552 tests   551 :heavy_check_mark:  2m 17s :stopwatch:     1 suites      0 :zzz:     1 files        1 :x:

For more details on these failures, see this check.

Results for commit f87c4b30.

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

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
gei	81%	87%	427	✔
ado2gh	88%	83%	579	✔
bbs2gh	74%	65%	264	➖
Octoshift	90%	78%	815	✔
Summary	86% (5330 / 6215)	79% (1164 / 1470)	2085	✔

[dylan-smith]

Closing this PR as we've redone the changes in #953