community, org: generate yaml with list of users access levels (#3500)

* community, org: generate yaml with list of users access levels

Adds a tool robots/cmd/org-access-check that generates a yaml document
with the access levels all the users have per a repository.

The yaml is structured like this:

```yaml
{access-level}:
    {repository}:
        - {user1}
        - ...

where access level is (admin|write|maintain)

See explanations on repository roles here [1]

[1]: https://docs.github.com/en/organizations/managing-user-access-to-your-organizations-repositories/managing-repository-roles/repository-roles-for-an-organization#repository-roles-for-organizations

Signed-off-by: Daniel Hiller <[email protected]>

* community, access: output yaml files with access

Will actually output three yaml files, looking from different angles:

* accessPermissions To Repositories To Collaborators
* repositories To AccessPermissions To Collaborators
* collaborators To AccessPermissions To Repositories

Signed-off-by: Daniel Hiller <[email protected]>

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Signed-off-by: Daniel Hiller <[email protected]>