Fixes coverall, #1755

Add tutorial for GKE with workload identity

Add instructions for using GKE workload identity to allow ExternalDNS
to authenticate against Google Cloud DNS APIs. Add blog link to
README.
Signed-off-by: David Dooling <dooling@gmail.com>

Enable azure_private_dns to work with non "AzurePublicCloud" clouds

Move Inactive Maintainers To Emeritus Approvers

Add Cloudflare documentation on use of `--zone-id-filter`

Updated FAQ for usage of annotation-filter

Fix index out of range when hostname has no dots

docs: enhance pull request template

* Added unit tests to the checklist
* Added end user docs to the checklist
* Added link to the contributing docs
* Added section for description and issue links

provide documentation of available prometheus metrics

A table of the available metrics is provided so end users do not have to
dig through the code to determine what metrics they have available to
them at runtime.

Co-authored-by: Raffaele Di Fazio <difazio.raffaele@gmail.com>

remove unused field IstioIngressGatewayServices

utilize the errors package for error handling

Update Documentation with Updated Registry Location

add license header check to the CI

Add test to verify NewAzurePrivateDNSProvider will use the ResourceManagerEndpoint from the configured cloud