allow to grant mod trust to groups

To use mod in an isolated environment without internet access(Spotfire Server, Web Player, Analyst,etc), we have been trying to figure out the best solution to eliminate the prerequisite that each user much perform trust action on each mod used, one solution to this problem is to create an unsigned mod and make it be trusted by all users.

The reason why we want to create an unsigned mod is to avoid ocsp validation against the original spotfire server that was used to sign the mod, when mod is migrated to other environment(e.g. dev -> prod)

There is no easy way to do this (make each unsigned mod be trusted by all users) for now, it would hugely reduce the management cost if one can grant mod trust on group level, preferably from "Users & Groups" web page.