AWSSD: Cleanup empty Services

[voro015]

Description

AWSSD provider aka AWS CloudMap should remove CloudMap Services when its last Instance de-registered.

• Added new flag aws-sd-service-cleanup to enable cleanup of stale CM Services, by default it will work as before;
  Opened for another flag name
• Updated submitCreates to respect Service ownership and update only "owned" Services
• Added DeleteService handler to cleanup empty CM Services from CloudMap using DeleteService API
• Updated AWSSDProvider struct to include ownerID and cleanEmptyService flag;
  I'm not sure if it could be done without updating provider struct without heavy-lifting.
  In current awssd implementation only registry is aware of TXTOwnerID and it cannot be easily passed without changing Provider interface, same time only provider aware when last Instance was Deregistered(Service cannot be deleted until all Instances are gone).
• Updated tests

Fixes #2509

This feature is critical when external-dns is used with awssd provider on high scale of Endpoints, when no cleanup preformed at some point CM Namespace will contain mostly orphaned empty CM Services and reconciliation will take tens of minutes to run.

Checklist

• Unit tests updated
• End user documentation updated

[njuettner]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: njuettner, voro015

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [njuettner]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment