R1:c97040de4707

Conpherence - get the durable column header actions working correctly

Summary:
Ref T7014. This diff addresses

- getting it to be the right set of options
- add participant
- view in conpherence
- close window
- making those options work
- make it so if you are on /conpherence/ you can't toggle the durable column

Test Plan: inspected dom via chrome tools and found last transaction. added a participant and inspected the single new transactin added for accuracy. used view in conpherence action…