[Thread] add command to force stop ot-daemon

The Thread HAL supports only one client for a single Thread chip, so
ot-daemon needs to be force stopped in VTS tests because the testapp
needs to connect to the HAL service to perform tests.

Bug: 328538612
Change-Id: I5288e5747ab3957050d0e85c1ea684c6ead6c87d
8 files changed