oe-selftest: devtool: check example services are running

oe-selftest: devtool: check example services are running

When running the devtool ide-sdk test with qemu, verify that the example
services are actually running on the target by using pgrep to check for
the example executable names.

Also verify that the configuration files in /etc are owned by the proper
user and group, both before and after the install_and_deploy scripts
have run. This is also a check that the install_and_deploy scripts
are working correctly with pseudo.

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>