Control view restrictions of the Environment Variable values

### Description

> Requested by @biancode

@biancode runs multiple teams in FlowForge for their various customer projects. In each team, they invite their respective customers, and developer their flows, but provide the customers access to their configuration/flows, etc.

one thing that they do not want to be giving customers access to though are some of the values of their environment variables/secrets.

After talking it through, we came to the conclusion that the option of a Team Owner being able to control whether or not the Environment Variable values (on a var by var basis) can be seen by Team Members would be a good solution for this.

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate