Feature: Distributed DNS

[philbrookes]

Kuadrant Operator changes

• dnspolicy: Set RoutingStrategy in DNSPolicy CRD as immutable kuadrant-operator#450
• dnspolicy: Update LB CNAME generation for loadbalanced strategy  kuadrant-operator#451
• dnspolicy: Add clusterID kuadrant-operator#452
• dnspolicy: Aggregate DNSRecord status kuadrant-operator#454

DNS Operator changes

• Add rootHost to DNS Record spec dns-operator#50
• Update DNS Record status from zone dns-operator#33
• Schedule removal of finalizer from DNS Records dns-operator#38
• Record write attempts in status for current generation dns-operator#34
• Re-queue DNS Record whenever a write to the Cloud Provider occurs dns-operator#35
• Re-queue validation intermittently dns-operator#36
• Record clashing DNS Policy configs that are overwriting each other. dns-operator#40

Distributed DNS:

• Add external-dns as a dependency dns-operator#47
• Update default registry to the TXT Registry dns-operator#48
• Implement multi cluster plan and registry dns-operator#49

Health Checks:

• Remove provider agnostic health check monitor dns-operator#45
• Add AWS Provider Health Checks dns-operator#44

Testing

• Review E2E Test Suite dns-operator#46
• Add basic multi-instance e2e scale test for DNS Operator dns-operator#121

Docs

• Update DNSPolicy ref docs
• Update DNSPolicy guides