Async send always-online counterparty side #20097

Job	Run time
coverage	23m 3s
build-tx-sync (ubuntu-latest, stable)	4m 59s
build-tx-sync (ubuntu-latest, 1.75.0)	6m 1s
build-tx-sync (macos-latest, stable)	6m 53s
check_release	1m 28s
build-tx-sync (ubuntu-latest, beta)	4m 47s
build (macos-latest, 1.63.0)	7m 42s
ext-test	8m 17s
benchmark	17m 5s
build (self-hosted, 1.63.0)	13m 52s
build (self-hosted, stable)	14m 4s
build (macos-latest, stable)	15m 24s
build (windows-latest, stable)	18m 28s
build (self-hosted, beta)	12m 49s
build-tx-sync (macos-latest, 1.75.0)	10m 39s
build-tx-sync (macos-latest, beta)	6m 57s
fuzz	13m 23s
rustfmt	14s
linting	57s
	3h 7m 2s

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