Add support to install collections from git repositories

[s-hertel]

SUMMARY

Fixes #61680

This adds support for installing collections from git repositories. Use the format git+URI,version (or git@URI,version to use ssh authentication) instead of a collection name. The version is optional and should be a git tree-ish instead of a collection artifact version. The version defaults to HEAD.

A repo can contain multiple or an individual collection. You can append #/path/to/collection/ to the URI to install collections from a particular directory in the repository.

This also adds a new type option for collection requirements files (which may be one of 'galaxy', 'file', 'url', or 'git' to override implicitly determining the type from the name field).

collections:
  - name: git@github.com:my_org/private_collections.git#/path/to/collection,devel
  - name: https://github.com/ansible-collections/amazon.aws.git
    type: git
    version: 8102847014fd6e7a3233df9ea998ef4677b99248

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

ansible-galaxy

[s-hertel]

cc @geerlingguy (since I can't request your review)

[jborean93]

Looks good, just a few docs questions and some behaviour around subdir checks

[webknjaz]

Pro tip: you can often get rid of escaping when using YAML blocks:

Suggested change

	- "'namespace_1.collection_1' in installed_collections.stdout"
	- "'namespace_2.collection_2' in installed_collections.stdout"
	- >-
	'namespace_1.collection_1' in installed_collections.stdout
	- >-
	'namespace_2.collection_2' in installed_collections.stdout

[s-hertel]

👍 I like the escaping better than the extra lines though in this case.

[webknjaz]

That linter error should probably be suppressed because this module runs on the controller AFAIU