Netbox-tunnels2

* Added Netbox 3.7 support
* Renamed the Tunnel model to PluginTunnel to allow for compatibility with Netbox v3.7<br>
Please plan to migrate from `netbox-tunnels2` to the native [Netbox VPN Tunnels model](https://docs.netbox.dev/en/stable/features/vpn-tunnels/)

* Added Netbox 3.6 support

* Add related tunnels to side A interfaces by p-rintz in https://github.com/robertlynch3/netbox-tunnels2/pull/14
* Fix permissions for non-admin users by p-rintz in https://github.com/robertlynch3/netbox-tunnels2/pull/16
* Allow VM assignment to tunnels by p-rintz in https://github.com/robertlynch3/netbox-tunnels2/pull/18

* Add Tenancy support to tunnels by p-rintz in https://github.com/robertlynch3/netbox-tunnels2/pull/12
* Fix title & align custom fields in template by p-rintz in https://github.com/robertlynch3/netbox-tunnels2/pull/13

* Added the blocks for rendering extra content by registered plugins

* Resolved [4](https://github.com/robertlynch3/netbox-tunnels2/issues/4)