feat(rbx_api): add update user role and list group roles endpoints

[memorycode]

Adds two new endpoints using groups v1:

• update_user_role (changes a users role in a group)
• get_all_roles (retrieves all roles for a specific group, useful for getting role_id for update_user_role)

A few notes:

1. There are probably better names
2. I wonder if these should be scoped to RobloxApi::groups::...

[vercel[bot]]

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Name	Status	Preview	Comments	Updated
mantle-docs	✅ Ready (Inspect)	Visit Preview	💬 Add your feedback	Feb 22, 2023 at 8:42PM (UTC)

[blake-mealey]

Please fix the lint warnings (see the failing CI pipeline) and then this is good to go