create smithy plugin to generate BDD ruleset

[sbiscigl]

Issue #, if available:

#2880

Description of changes:

Adds a flag --use-smithy-bdd-endpoints that will enable a smithy plugin to generate a BDD rules set representation and swap clients to use a BDD endpoint provider by default. from preliminary testing we see a large reduction in client contruction time and endpoints resolution time in the S3 Client

Benchmark	JSON	BDD	Δ	Speedup
s3 client construction	750,135 ns	30,639 ns	−95.9%	24.5×
steady state resolve on virtual addressing	6,006 ns	3,312 ns	−44.9%	1.81×

This PR will NOT trigger generation, a follow up PR will swap the default value, and move clients to the new endpoint provider.

Check all that applies:

• Did a review by yourself.
• Added proper tests to cover this PR. (If tests are not applicable, explain.)
• Checked if this PR is a breaking (APIs have been changed) change.
• Checked if this PR will not introduce cross-platform inconsistent behavior.
• Checked if this PR would require a ReadMe/Wiki update.

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[pulimsr]

nit: Could this false-positive if smithy.rules#endpointBdd appears in a documentation field or other string value in the JSON? It's a substring search over the entire file contents.

[sbaluja]

A substring search in the entire model seems shady to me, can we use actual json/trait parsing since we know exactly where this trait will live on the model?

ex.

def bdd_endpoint_services():
      """C2J service names whose Smithy model carries the endpointBdd trait on its service shape,
      i.e. the services the Smithy generator will emit a BDD blob for. C2J must skip its JSON
      endpoint-rules blob for exactly this set; services outside it (legacy/mock, or models lacking
      the trait) keep the JSON path. This MUST stay in sync with EndpointRulesCodegenPlugin's
      service.hasTrait(ENDPOINT_BDD_TRAIT) check — divergence causes a missing GetRulesBlob() symbol."""
      with open(os.path.abspath(SMITHY_TO_C2J_MAP_FILE), 'r') as file:
          smithy_to_c2j = json.load(file)
      descriptions_dir = os.path.abspath(SMITHY_API_DESCRIPTIONS_DIR)
      services = set()
      for f in os.listdir(descriptions_dir):
          if not f.endswith(".json"):
              continue
          sdk_id = f[:-len(".json")]
          model = json.loads(Path(descriptions_dir, f).read_text())
          has_bdd = any(
              shape.get("type") == "service" and ENDPOINT_BDD_TRAIT in shape.get("traits", {})
              for shape in model.get("shapes", {}).values()
          )
          if has_bdd:
              services.add(smithy_to_c2j.get(sdk_id, sdk_id))
      return services

[sbaluja]

We're duplicating functionality here. ServiceNameUtilJava.sanitizeServiceAbbreviation does this already

[sbaluja]

Eventually we'll need this functionality for client generation. Should this be in ServiceNameUtil?