Implement RemoveBetaTester(s)FromGroup(s)

[DechengMa]

Closes #110

📝 Summary of Changes

• Create two commands: RemoveTestersFromGroupCommand and RemoveTesterFromGroupsCommand
• Create RemoveTesterOperation which can take two kinds of options
• Create two service functions removeTesterFromGroups and removeTestersFromGroup

🧐🗒 Reviewer Notes

💁 Example

Usage: asc testflight betatesters removegroup <email> <group-names> asc testflight betagroup removeuser <group-name> <emails>

🔨 How To Test

asc testflight betatesters removegroup foo@gmail.com TestGroup1 TestGroup2 asc testflight betagroup removeuser TestGroup1 foo@gmail.com bar@gmail.com