Add signature_version support to storage-cli S3 config templates

[ybykov-a9s]

The storage-cli S3 client accepts an optional signature_version
parameter, but the connection_config sub-options were not being
extracted into the rendered storage_cli_config_*.json files, so the
value was silently dropped even when operators set it.

Add signature_version passthrough to all storage_cli_config_*.json.erb
templates in cloud_controller_ng, cloud_controller_worker,
cloud_controller_clock, cc_deployment_updater, and blobstore_benchmark,
and cover it in the corresponding storage_cli_config_jsons_spec.rb specs.

Github Copilot AI (Claude Sonnet 5) was used to identify all locations requiring changes
and to draft the PR message.

• I have viewed signed and have submitted the Contributor License Agreement

• I have made this pull request to the develop branch

• I have run CF Acceptance Tests on bosh lite

[johha]

Thank you @ybykov-a9s for the contribution. The changes look good overall.
As you're a new contributor to CAPI I'd like to mention our AI tooling policy. In case you used AI for this PR it would be great if you could briefly mention it in the PR description.

[ybykov-a9s]

@johha Thank you for the remark. I updated the information regarding AI.

[johha]

LGTM