docs: samples for managing reservations

[tswast]

TODO: Testing these samples requires a capacity commitment. I created on manually on my dev project, but I think we'll want to programmatically create one in our CI project(s).

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Fixes #56 🦕

[snippet-bot]

Here is the summary of changes.

You are about to add 3 region tags.

• samples/snippets/reservation_create.py:26, tag bigqueryreservation_reservation_create
• samples/snippets/reservation_delete.py:21, tag bigqueryreservation_reservation_delete
• samples/snippets/reservation_update.py:26, tag bigqueryreservation_reservation_update

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[tswast]

args = (parent: "projects/python-docs-samples-tests/locations/US"
capacity_commitment {
  slot_count: 100
  plan: FLEX
}
,)
kwargs = {'metadata': [('x-goog-request-params', 'parent=projects/python-docs-samples-tests/locations/US'), ('x-goog-api-client', 'gl-python/3.6.13 grpc/1.39.0 gax/1.31.1 gapic/1.2.2')]}

    @six.wraps(callable_)
    def error_remapped_callable(*args, **kwargs):
        try:
            return callable_(*args, **kwargs)
        except grpc.RpcError as exc:
>           six.raise_from(exceptions.from_grpc_error(exc), exc)
E           google.api_core.exceptions.FailedPrecondition: 400 Google owned projects are not allowed to buy FLEX slots, please see go/bq-flex-restrictions for details.

.nox/py-3-6/lib/python3.6/site-packages/google/api_core/grpc_helpers.py:69: FailedPrecondition
- generated xml file: /tmpfs/src/github/python-bigquery-reservation/samples/snippets/sponge_log.xml -

I've requested FLEX slot usage in internal bug 196099709

[tswast]

It worked! We can now use FLEX commitments on the samples project.

[jamiet-msm]

@tswast Hugely appreciate you providing these samples, saved me a big job. I was specifically looking for an example for update_reservation, the field_mask stuff was non-obvious to me.

[tswast]

@tswast Hugely appreciate you providing these samples, saved me a big job. I was specifically looking for an example for update_reservation, the field_mask stuff was non-obvious to me.

@jamiet-msm I'm so glad that you found them helpful. Thanks for the feedback.