Add support for converting Ingress resource and its annotations to valid NGF specs

[salonichf5]

As a cluster operator
I want to be able to migrate from Ingress Resources in NIC to NGF
So that I am able support users to are migrating from NIC to NGF

Acceptance Criteria:

• Plan and document the annotations that will be converted to NGF resources
• Provide conversion support by reading both from file and cluster
• Unit tests
• Added documentation (Readme) on resources currently supported
• PR in ingress2gateway repo

[salonichf5]

Just wanted to put on note here so that its helpful during reviews

As discussed in Slack, here are a few working assumptions we’re following for the conversion tool:

• Each Ingress spec translates to a single Route.
• We are not validating the existence of applications or secrets referenced in the translated spec within the cluster.
• If multiple HTTPS listeners share the same hostname, port, protocol and TLS cert they will be combined into a single HTTPS listener in the NGF spec.
• That we are always converting a valid ingress spec to gateway fabric spec.
• Since validation for securing backend traffic is different in for ingress and gateway( NIC secures traffic based on service name and NGF secures traffic based on the TLS cert & hostname & service name in BackendTLSPolicy) , we are leaving these fields (TLS certs and Hostname) empty for the customer to configure with a warning notification.

[salonichf5]

PR for this story in ingress2gateway repo