[eas-cli] add init:onboarding flow for no gh repo connected

[szdziedzic]

Why

add init:onboarding flow for no gh repo connected

How

• clone default expo template
• reset git repo
• generate needed app.json and eas.json
• install expo libs (updates, dev client, insights)
• run a build

Test Plan

test manually

[github-actions]

Size Change: -7.95 kB (-0.02%)

Total Size: 51.3 MB

Filename	Size	Change
./packages/eas-cli/dist/eas-linux-x64.tar.gz	51.3 MB	-7.95 kB (-0.02%)

_{compressed-size-action}

[codecov]

Codecov Report

Attention: Patch coverage is 11.00000% with 89 lines in your changes are missing coverage. Please review.

Project coverage is 53.47%. Comparing base (6dc9253) to head (043d088).
Report is 7 commits behind head on main.

Files	Patch %	Lines
...ackages/eas-cli/src/commands/project/onboarding.ts	11.54%	66 Missing and 3 partials ⚠️
packages/eas-cli/src/vcs/clients/git.ts	10.00%	8 Missing and 1 partial ⚠️
packages/eas-cli/src/build/runBuildAndSubmit.ts	0.00%	8 Missing ⚠️
packages/eas-cli/src/onboarding/runCommand.ts	0.00%	1 Missing ⚠️
packages/eas-cli/src/utils/expoUpdatesCli.ts	0.00%	1 Missing ⚠️
packages/eas-cli/src/vcs/git.ts	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2373      +/-   ##
==========================================
- Coverage   53.56%   53.47%   -0.08%     
==========================================
  Files         530      530              
  Lines       19512    19494      -18     
  Branches     4134     3955     -179     
==========================================
- Hits        10449    10422      -27     
+ Misses       8332     8320      -12     
- Partials      731      752      +21     

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[tchayen]

The onboarding-related parts look good to me.

Ideally in future we would be able to avoid repeating the backend code but for now I don't see any obvious way to do it.

[github-actions]

⏩ The changelog entry check has been skipped since the "no changelog" label is present.