RFE: Ability to restrict use of insecure options for user-defined containers

**Setup**
Jenkins version: 2.138
Docker Plugin version: 1.1.5

**Motivation**
We would like to isolate the builds of our development teams. Their build configs can already be isolated using the built-in permissions of Jenkins. However, on a file basis, there is no built-in way to separate the individual workspaces and processes because everything is being run using the same user. Using the Docker Plugin, it is theoretically possible to execute each build in a temporary container and thus isolating the individual builds. In practice, the Docker Plugin allows custom docker templates per build config which could be used to break the isolation. As an example, the build could run as root and also mount docker.sock or even activate privileged mode, which essentially grants root access to the host.

**Feature Request**
We are kindly requesting to
a) introduce a setting that disallows custom docker templates
b) alternatively, a possibility to disallow customizing specific settings (like volumes, user, image or privileged mode)

This should be sufficent to isolate the individual builds.