Add v3 api to list all roles that the user has on the project

[gtema]

https://docs.openstack.org/api-ref/identity/v3/index.html?expanded=check-whether-user-has-role-assignment-on-project-detail#list-role-assignments-for-user-on-domain

[konac-hamza]

If it's ok with you, I'd like start working on this issue?

[gtema]

Sure