* feature: Add a 'session' sensor type
This allows things like the SRX5800 SPU's to be graphed as they expose current and maximum usage in a table.
The intent is to contain things like TTY sessions, flow counters from other vendors, or other resources with support a finite number of simultaneous users or connections.
* Include the node description in the descr field
Chassis clusters use the same FPC's
* Track PanOS session count
* Add JunOS CP Flows
* Missed file containing overview
* Missed a spot
* remove custom sessions sensor and use count
* Update junos.yaml
* Update panos.yaml