[test] add external commissioner tests (#5187)
[test] add external commissioner tests (#5187)

This adds tests of ot-commissioner as part of GitHub Action workflows.
srickardti/openthread,lanyuwen/openthread,lanyuwen/openthread,srickardti/openthread,bukepo/openthread,abtink/openthread,chshu/openthread,abtink/openthread,bukepo/openthread,chshu/openthread,chshu/openthread,openthread/openthread,chshu/openthread,openthread/openthread,lanyuwen/openthread,bukepo/openthread,srickardti/openthread,chshu/openthread,jwhui/openthread,abtink/openthread,lanyuwen/openthread,chshu/openthread,srickardti/openthread,jwhui/openthread,lanyuwen/openthread,jwhui/openthread,openthread/openthread,lanyuwen/openthread,openthread/openthread,abtink/openthread,bukepo/openthread,jwhui/openthread