Add tokio taskname registration for use in tokio-console #635

Job	Run time
Lints	42s
Documentation	17s
Minimal Dependency Versions	20s
Build Examples	2m 40s
Build (aarch64-unknown-linux-gnu)	3m 56s
Memory leaks	3m 38s
Build (x86_64-pc-windows-gnu)	1m 1s
Minimal Dependency Versions (MSRV)	34s
Minimum Supported Rust Version	22s
Build (x86_64-unknown-linux-gnu)	1m 4s
Semantic Versioning	26s
Test Suite	3m 32s
Publish version	0s
	18m 32s

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