Impl WasmType for FuncRef and ExternRef

[Robbepop]

This allows to use FuncRef and ExternRef types with the TypedFunc API and everything that connects to it.

This functionality was trivial to add and simply forgotten in the reference-types Wasm proposal implementation PR.

[paritytech-cicd-pr]

BENCHMARKS

	NATIVE			WASMTIME
BENCHMARK	MASTER	PR	DIFF	MASTER	PR	DIFF	WASMTIME OVERHEAD
execute/ bare_call_0	1.47ms	1.42ms	🔴 -2.79%	1.14ms	1.18ms	🔴 2.59%	🟢 -17%
execute/ bare_call_0/typed	1.02ms	1.03ms	🔴 1.43%	785.56µs	791.10µs	⚪ -0.77%	🟢 -24%
execute/ bare_call_1	1.45ms	1.46ms	🔴 0.81%	1.37ms	1.38ms	🟢 0.46%	🟢 -6%
execute/ bare_call_16	2.49ms	2.46ms	🟢 -1.19%	4.48ms	4.51ms	⚪ 0.87%	🟡 84%
execute/ bare_call_16/typed	1.80ms	1.80ms	⚪ 0.17%	2.78ms	2.80ms	⚪ 0.81%	🟡 56%
execute/ bare_call_1/typed	1.13ms	1.16ms	🔴 2.62%	1.18ms	1.16ms	🟢 -1.36%	🟢 0%
execute/ bare_call_4	1.71ms	1.61ms	🟢 -5.79%	2.02ms	2.02ms	⚪ 0.15%	🟢 26%
execute/ bare_call_4/typed	1.18ms	1.15ms	⚪ -1.45%	1.31ms	1.33ms	⚪ 1.27%	🟢 15%
execute/ br_table	1.19ms	1.15ms	🟢 -2.99%	1.36ms	1.35ms	⚪ -2.71%	🟢 17%
execute/ count_until	1.23ms	683.71µs	🟢 -44.15%	2.22ms	2.13ms	🟢 -4.61%	🔴 211%
execute/ factorial_iterative	330.35µs	328.20µs	⚪ -0.81%	947.29µs	948.02µs	⚪ -0.08%	🔴 189%
execute/ factorial_recursive	686.94µs	668.15µs	🟢 -2.60%	1.38ms	1.34ms	🟢 -2.40%	🔴 101%
execute/ fib_iterative	1.40ms	1.40ms	⚪ -0.16%	5.15ms	5.15ms	⚪ 0.15%	🔴 269%
execute/ fib_recursive	5.92ms	5.93ms	⚪ 0.34%	11.94ms	11.77ms	⚪ -1.13%	🟡 98%
execute/ global_bump	984.18µs	984.04µs	⚪ -0.30%	2.50ms	2.45ms	🟢 -1.84%	🔴 149%
execute/ global_const	741.66µs	743.36µs	⚪ 0.20%	2.55ms	2.56ms	⚪ 0.66%	🔴 245%
execute/ host_calls	26.31µs	26.54µs	⚪ 1.16%	40.24µs	39.60µs	⚪ -1.25%	🟢 49%
execute/ memory_fill	1.26ms	1.25ms	⚪ -0.05%	4.15ms	4.16ms	⚪ 0.18%	🔴 232%
execute/ memory_sum	1.27ms	1.20ms	⚪ -6.24%	4.15ms	4.15ms	⚪ -0.06%	🔴 247%
execute/ memory_vec_add	2.60ms	2.60ms	⚪ 0.09%	7.59ms	7.61ms	⚪ 0.07%	🔴 192%
execute/ recursive_is_even	1.14ms	1.13ms	⚪ -0.37%	2.38ms	2.37ms	⚪ -1.51%	🔴 109%
execute/ recursive_ok	158.95µs	162.54µs	🔴 2.09%	346.17µs	311.14µs	🟢 -10.24%	🟡 91%
execute/ recursive_scan	183.40µs	183.11µs	⚪ -0.59%	412.68µs	374.79µs	🟢 -9.04%	🔴 105%
execute/ recursive_trap	16.45µs	15.95µs	🟢 -2.88%	29.75µs	29.69µs	⚪ -0.19%	🟡 86%
execute/ regex_redux	538.85µs	528.07µs	🟢 -1.93%	1.41ms	1.39ms	⚪ -0.96%	🔴 164%
execute/ rev_complement	486.80µs	511.23µs	🔴 5.08%	1.43ms	1.42ms	⚪ -0.50%	🔴 178%
execute/ tiny_keccak	333.93µs	349.47µs	⚪ 13.42%	1.16ms	1.15ms	⚪ -0.71%	🔴 230%
execute/ trunc_f2i	736.33µs	734.55µs	⚪ -0.23%	2.13ms	2.13ms	⚪ -0.41%	🔴 190%
instantiate/ wasm_kernel	65.84µs	65.88µs	⚪ 2.33%	72.87µs	72.42µs	⚪ -0.34%	🟢 10%
translate/ erc1155	205.88µs	216.41µs	⚪ 2.53%	389.58µs	391.24µs	⚪ 0.17%	🟡 81%
translate/ erc20	101.74µs	102.65µs	⚪ 0.54%	189.51µs	192.07µs	⚪ 1.29%	🟡 87%
translate/ erc721	143.95µs	146.21µs	⚪ 0.77%	277.14µs	277.63µs	⚪ 0.54%	🟡 90%
translate/ spidermonkey	0.00ns	0.00ns	⚪ 0.71%	0.00ns	0.00ns	🔴 1.51%	🟢 0%
translate/ wasm_kernel	3.72ms	3.72ms	⚪ 0.27%	7.36ms	7.38ms	⚪ -0.56%	🟡 98%

Link to pipeline