[salsa] Add control over multiple features

New:

• analytics_access_level
• auto_devops_enabled
• builds_access_level
• container_registry_access_level
• forking_access_level
• lfs_enabled
• packages_enabled
• pages_access_level
• releases_access_level
• repository_access_level
• request_access_enabled
• requirements_access_level
• snippets_access_level
• wiki_access_level

Upgraded (was using legacy API variables which didn't support "private" option):

• issues_access_level
• merge_requests_access_level