feat: add sonic testnet (#110) #395

Job	Run time
miri --no-default-features	46s
test stable --no-default-features	18s
miri	45s
wasm	22s
test stable	21s
feature-checks	55s
miri --all-features	1m 5s
test stable --all-features	26s
test beta --no-default-features	22s
clippy	28s
test beta	23s
docs	28s
fmt	10s
test beta --all-features	33s
test nightly --no-default-features	22s
test nightly	23s
test nightly --all-features	29s
test 1.79 --no-default-features	21s
test 1.79	21s
	9m 18s

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