Once libmongocrypt supports the new "substring" query type name, block the deprecated "substringPreview" string at collection creation and CRUD time. See SERVER-123416 for an example blocking the deprecated "suffixPreview" and "prefixPreview" types.

Acceptance Criteria:

Change the following

• Collection creation (src/mongo/db/shard_role/ddl/create_command.cpp) — Add uassert calls to reject "SubstringPreviewDeprecated" at collection creation, matching the existing pattern from SERVER-123416.

• (src/mongo/crypto/fle_crypto.cpp — getAndValidateSchema) — Add uassert calls to reject operations on collections that still use "SubstringPreviewDeprecated", prompting users to recreate with the new "Substring". This matches the existing CRUD-time blocking from SERVER-123416.
• Address all "TODO"s marking places in the code where substringPreview should be updated to substring (e.g. src/mongo/db/modules/enterprise/jstests/no_passthrough/fle2_create_collection_invalid_text_opts.js)