[8.19](backport #3893) fix project metadata request

[mergify]

Changes

• add rate limiting for GCP Projects API to prevent 429 quota errors
• add singleflight to deduplicate concurrent requests for the same project metadata

Context

• a while ago i merged a PR to cache the org name so we don't get rate limited for the org api.
• latest errors show we're hitting rate limit errors for project api, this is what this PR fixes

googleapi: Error 429: Quota exceeded for quota metric 'Project V3 get requests' 

The quota is 600 requests per minute. with many projects and assets arriving concurrently, we could exceed this before the cache was populated.

---

This is an automatic backport of pull request #3893 done by Mergify.

[mergify]

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Changes to be committed:
	modified:   internal/resources/fetching/fetchers/gcp/assets_fetcher.go
	modified:   internal/resources/fetching/fetchers/gcp/assets_fetcher_test.go
	modified:   internal/resources/fetching/fetchers/gcp/log_sink_fetcher.go
	modified:   internal/resources/fetching/fetchers/gcp/log_sink_fetcher_test.go
	modified:   internal/resources/fetching/fetchers/gcp/monitoring_fetcher.go
	modified:   internal/resources/fetching/fetchers/gcp/monitoring_fetcher_test.go
	modified:   internal/resources/fetching/fetchers/gcp/networks_fetcher.go
	modified:   internal/resources/fetching/fetchers/gcp/networks_fetcher_test.go
	modified:   internal/resources/fetching/fetchers/gcp/policies_fetcher.go
	modified:   internal/resources/fetching/fetchers/gcp/policies_fetcher_test.go
	modified:   internal/resources/fetching/fetchers/gcp/service_usage_fetcher.go
	modified:   internal/resources/fetching/fetchers/gcp/service_usage_fetcher_test.go
	modified:   internal/resources/providers/gcplib/inventory/resource_manager.go
	modified:   internal/resources/providers/gcplib/inventory/resource_manager_test.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally