feat!: Add support for creating GitHub App with organizations

[wenked]

Fixes: #3210.

BREAKING CHANGE: The CreateApp function now requires two arguments: AppManifest and orgName, to support creating apps with organizations.

The issue occurred because the create app URL path was only set up for creating personal GitHub apps.

My solution was to add an additional argument to the function to provide the necessary information for creating organizational GitHub Apps. The second argument, AppConfig, now includes configuration structs with an OwnerType that can be either personal or organizational, and you can provide the organization name by passing OrgName in the AppConfig struct.

For more details, see the issue: #3210.

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[gmlewis]

Thank you, @wenked !
Please address the few minor comments.

@willnorris - since this involves scrape, do you have any comments or concerns regarding the breaking change in this PR?

[gmlewis]

We'll see what @willnorris says, but we could alternatively have a second ...ForOrgs method if the breaking API change is unwanted.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.94%. Comparing base (2b8c7fa) to head (d6cf6fa).
Report is 89 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3222 +/- ##
==========================================
- Coverage 97.72% 92.94% -4.78% 
==========================================
Files 153 171 +18 Lines 13390 11633 -1757 ==========================================
- Hits 13085 10812 -2273 - Misses 215 727 +512 - Partials 90 94 +4 

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[willnorris]

I don't have any sense on who is using this package (not many people, looking at pkg.go.dev), so I don't have strong feelings either way on the change. looks fine to me.

[gmlewis]

Thank you, @wenked !
LGTM.
Merging.