feat: postMessage API #548

Job	Run time
Build & static code analysis	2m 32s
Check changeset	2m 5s
Android road test (RNApp & AndroidApp - Vanilla)	15m 27s
iOS road test (RNApp & AppleApp - Expo)	14m 55s
iOS road test (RNApp & AppleApp - Vanilla)	11m 43s
iOS road test (TesterIntegrated)	4m 9s
Android road test (RNApp & AndroidApp - Expo)	33m 56s
Android road test (TesterIntegrated)	13m 21s
	1h 38m 8s

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