[NET-546] Move ee code to ee package, unify ee status and terminology (#2538)

* Move ee code to ee package and unify ee status to IsPro

* Consolidate naming for paid/professional/enterprise version as "pro". Notes:

- Changes image tags
- Changes build tags
- Changes package names
- Doesn't change links to docs that mention "ee"
- Doesn't change parameters sent to PostHog that mention "ee"

* Revert docker image tag being -pro, back to -ee

* Revert go build tag being pro, back to ee

* Add build tags for some ee content

* [2] Revert go build tag being pro, back to ee

* Fix test workflow

* Add a json tag to be backwards compatible with frontend "IsEE" check

* Add a json tag for the serverconfig struct for IsEE

* Ammend json tag to Is_EE

* fix ee tags

---------

Co-authored-by: Abhishek Kondur <abhi281342@gmail.com>

logic/gateway.go

@@ -148,7 +148,7 @@ func CreateIngressGateway(netid string, nodeid string, ingress models.IngressReq
 	node.IngressGatewayRange6 = network.AddressRange6
 	node.IngressDNS = ingress.ExtclientDNS
 	node.SetLastModified()
-	if ingress.Failover && servercfg.Is_EE {
+	if ingress.Failover && servercfg.IsPro {
 		node.Failover = true
 	}
 	err = UpsertNode(&node)