Consolidate default groups and permission settings

[tusmester]

There are redundant groups and permission settings throughout the default repository structure, we should simplify it:

• remove unnecessary entries
• move entries to a higher level if necessary
• remove unnecessary breaks
• workspace local permissions: if there are appropriate local groups, do not give the same permissions to global groups, just put the global group (admins, everyone, etc.) to the local group as a member [VALIDATE THIS, for example what if we need to preserve the rights of global groups from local admins...?]