Add support for ILB as next-hop with tags

[modular-magician]

Add Terraform Support for ILB as next hop with tags

Fixes hashicorp/terraform-provider-google#9833

One test is failing in the GA provider (TestAccComputeRoute_hopInstance) but I'm not sure it's realated to this change.

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• Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
• Generated Terraform, and ran make test and make lint to ensure it passes unit and linter tests.
• Ensured that all new fields I added that can be set by a user appear in at least one example (for generated resources) or third_party test (for handwritten resources or update tests).
• Ran relevant acceptance tests (If the acceptance tests do not yet pass or you are unable to run them, please let your reviewer know).
• Read the Release Notes Guide before writing my release note below.

Release Note Template for Downstream PRs (will be copied)

compute: allow passing an IP address to the `nextHopIlb` field of `google_compute_route` resource

Derived from GoogleCloudPlatform/magic-modules#5162