fix(crypto): support string encryption algorithm identifiers

[dills122]

Issue # (if available)

Related to #968.

Description of changes

Accept case-insensitive DOMString algorithm identifiers for parameterless AES-KW wrap/unwrap and RSA-OAEP encrypt/decrypt operations.

WebCrypto AlgorithmIdentifier accepts either a DOMString or an algorithm dictionary. The encryption parser previously required an object unconditionally, so valid string identifiers failed before AES-KW or RSA-OAEP could be selected. The parser now reuses the existing algorithm-name normalization path and permits omitted parameter objects only for those operations.

AES-CBC, AES-CTR, and AES-GCM continue to reject string-only inputs with TypeError because their required parameter dictionaries are absent. Object-based RSA-OAEP labels are also covered to ensure the parser change preserves non-empty label handling.

Relevant standard:

• Web Cryptography Level 2 — algorithm normalization

Validation:

• cargo test -p llrt_crypto — 23 passed
• focused LLRT crypto.subtle runtime suite — 20 passed
• cargo clippy -p llrt_crypto --all-targets -- -D warnings
• cargo fmt --all -- --check
• Prettier check for tests/unit/crypto.subtle.test.ts
• git diff --check
• complete fork CI matrix passed, including the successful rerun of a transient Homebrew setup failure

Checklist

• Created focused unit coverage for AES-KW, RSA-OAEP, required AES dictionaries, and RSA-OAEP labels
• Ran targeted Rust and TypeScript formatting checks
• Made sure the code adds no warnings with warning-denied Clippy and the CI check job
• Confirmed type changes are not applicable
• Confirmed documentation changes are not required

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.