Create custom groups of members to be added to teams

Originally from ticket #3418.

It would be nice to be able to make custom groups of individuals that could be added to a project or task with one click. This could be implemented by adding each group member as a team member when that group is selected when adding a team member.

In some cases users need to add a group of individuals (eg "Managers") to multiple projects. It would make this process easier and faster if they could put these groups together in one place and then reuse them across the application.

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Submitted from: https://col.connectionsonline.net/15/19e77172-7ab5-42e5-a974-a2cd0ff5b70e