internal/provider: add a new cockroach_private_endpoint_trusted_owner resource

[jaylim-crl]

NOTE: This PR depends on the following:

• Wait for a new CC production release
• Merge pkg: update API spec to latest cockroach-cloud-sdk-go#41
• Release a new version of cockroach-cloud-sdk-go (Update package version to 1.6.0 cockroach-cloud-sdk-go#42)
• Import that new version into terraform-provider-cockroach (vendor: update cockroach-cloud-sdk-go to v1.6.0 #160)

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internal/provider: add a new cockroach_private_endpoint_trusted_owner resource

This commit adds a new cockroach_private_endpoint_trusted_owner terraform
resource to manage private endpoint trusted owner entries.

docs: update docs to include cockroach_private_endpoint_connection

This commit updates the docs to include the new
cockroach_private_endpoint_connection resource. At the same time, we add
an example for such a resource, and update the CHANGELOG file as well.

---

Commit checklist

• Changelog
• Doc gen (make generate)
• Integration test(s)
• Acceptance test(s)
• Example(s)

[jaylim-crl]

Ran the acceptance tests against staging:

$ TF_ACC=1 go test -test.v -run TestAccDedicatedPrivateEndpointTrustedOwnerResource -timeout 120m -parallel 100 ./internal/provider/
=== RUN   TestAccDedicatedPrivateEndpointTrustedOwnerResource
--- PASS: TestAccDedicatedPrivateEndpointTrustedOwnerResource (1291.43s)
PASS
ok  	github.com/cockroachdb/terraform-provider-cockroach/internal/provider	1291.787s

We'd have to flip the feature flag on the right production org before releasing a new provider version.

[erademacher]

Textbook resource implementation. Very nice.

Reviewed 5 of 5 files at r2, 4 of 4 files at r3, all commit messages.
Reviewable status: 9 of 24 files reviewed, 1 unresolved discussion (waiting on @jaylim-crl, @jeffswenson, and @pjtatlow)

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internal/provider/private_endpoint_trusted_owner_resource.go line 59 at r2 (raw file):

				Computed: true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),

nit: I don't think this does anything for a computed field.

[jaylim-crl]

TFTR!