Adding support for roles in VOs

[tdviet]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Problem

Several user communities have roles/subgroups in VO. The fedcloud client should be aware of the existence of the roles and able to deal with them.

Solution

• Adding fedcloud token list-roles --vo vo-name for listing the roles of the user in the VO
• Check all commands of roles are properly mapped/supported

Alternatives

Nothing