feat: add RTCDataChannel id #1291

Job	Run time
build_benchmarks	1m 37s
build_examples	4m 15s
build_nightly	2m 38s
Check	2m 3s
Verify that web-sys is compiled correctly	1m 28s
Clippy	6m 11s
dist_linux_aarch64_gnu	4m 51s
dist_linux_x86_64_musl	3m 16s
dist_macos_aarch64	3m 58s
dist_macos_x86_64	3m 48s
dist_windows	3m 58s
doc_api	1m 47s
doc_book	18s
Rustfmt	17s
Build and test the deno example	1m 29s
Run js-sys crate tests	4m 16s
Run native tests	3m 29s
Run wasm-bindgen crate tests with multithreading enabled	4m 52s
Test TypeScript output of wasm-bindgen	1m 28s
Run UI compile-fail tests	2m 12s
Run wasm-bindgen crate tests (unix)	6m 38s
Run web-sys crate tests	4m 44s
Run wasm-bindgen-webidl crate tests	4m 19s
test_examples	3m 15s
deploy	1m 50s
	1h 18m 57s

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