feat: custom Node domains support in Inspector

[littledivy]

This patch lets us extend the Inspector protocol with new domains defined in src/deno_inspector/node_protocol.pdl. It also adds bindings to crdtp for sending notifcations and responses to protocol clients.

[kajukitli]

suggestion: the std::string_view in string_util.h could be replaced with const String& to stay consistent with the protocol's type aliases and avoid the C++ <string_view> dependency:

-  static const uint8_t* CharactersUTF8(const std::string_view s);
-  static size_t CharacterCount(const std::string_view s);
+  static const uint8_t* CharactersUTF8(const String& s);
+  static size_t CharacterCount(const String& s);

(same for CharactersLatin1 and CharactersUTF16)

v8 build works fine with this change, couldn't fully test locally due to bindgen needing clang 19+

[kajukitli]

this is a substantial PR — adding crdtp bindings and custom inspector protocol domains

overall architecture looks reasonable:

• crdtp.rs provides Rust bindings to V8's Chrome DevTools Protocol Transport
• crdtp_binding.cc is the C++ glue layer
• deno_inspector/ contains the PDL domain definitions

a few observations:

1. memory safety concerns — there's a lot of raw pointer handling and unsafe blocks. the FrontendChannel implementation with the custom CxxVTable is especially tricky. would be good to have thorough tests for memory leaks/use-after-free scenarios.

2. string_util.cc — i left a comment before about using const String& instead of std::string_view to stay consistent with the protocol's type aliases. was that considered?

3. test coverage — the test_api.rs additions look comprehensive for the happy path. any negative test cases (malformed CBOR, invalid method names, etc.)?

4. CI status — last i checked CI was failing due to OOM building V8. has that been resolved?

not blocking, but would like clarity on #2 and #4 before approving

[kajukitli]

lgtm — thanks for addressing all the feedback

changes since last review:

• std::string_view → const String& in string_util.h/cc ✅
• memory leak fixed: DomainDispatcher now properly freed via C++ destructor callback (crdtp__DomainDispatcher__BASE__Drop) ✅
• double-serialization fixed in Serializable::to_bytes() ✅
• added DropTracker test to verify cleanup ✅
• removed dead code (UberDispatcher::as_raw, unused SIZE function) ✅

CI is running now — assuming it passes, this is good to merge