Pre-select permissions when creating a custom role

What does this MR do and why?

Related to #467846 (closed)

This MR adds the frontend changes to pre-select abilities that are inherited from a base role when creating or viewing custom roles.

References

Please include cross links to any resources that are relevant to this MR. This will give reviewers and future readers helpful context to give an efficient review of the changes introduced.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Enable SaaS mode

   export GITLAB_SIMULATE_SAAS=1

2. In a group with an ultimate license navigate to Settings -> Roles and Permissions
3. Create a new custom role. The permissions included from the base access level should be reflected in the UI.
4. After the role is created select the newly created role. In the role details page you should also see which permissions were included from the base access level.