feat: add back helper for generating "parent" path

[bcoe]

In v3 of the translate API, we are requiring that folks generate a full parent path when interacting with the API:

parent: `projects/${projectId}/locations/${location}`,

This is fairly unwieldy, and we should reintroduce a helper for this.

CC: @alexander-fenster, @nnegrey

[alexander-fenster]

Will be later this week. This will be a compatible change (just adding a few methods). @xiaozhenliu-gg5 is working on it in the generator.

[arcman77]

When I look at my project storage bucket in the gcp (or if I query the bucket's metadata from the command line) the value for the location field just says "us (multiple regions in United States)" (or "US")

Am I supposed to assume that it should be "us-central1"?

[nnegrey]

@arcman77, feel free to open a separate issues for this as that is a little different, but there are different types of cloud storage buckets.
Regions and multi-regions. Sounds like you have a multi-regional bucket.
https://cloud.google.com/storage/docs/locations#available_locations

The translation api currently supports two regions (global and us-central1)
"""
Note: All your resources in a single request to Translation API - Advanced must have the same location. Currently, only global and us-central1 locations are supported. For all custom resources—AutoML models, glossaries, long-running-operations—you must use us-central1. You can also use us-central1 for general translation and language detection. The global location can only be used for general translation models and language detection.
"""
From https://cloud.google.com/translate/docs/migrate-to-v3#resources_projects_and_locations

But the bucket location is only required if you are trying to use custom resources, if you are not, then global should be all you need.

[JustinBeckwith]

Moving this over to gax since I suspect this would need to be fixed there?

[alexander-fenster]

I guess it's the gapic-generator-typescript and maybe it's just a dup of googleapis/gapic-generator-typescript#570, but I'll take a look anyway.