Put testtool startup into its own testcase

Put testtool startup into its own testcase

The Install_And_Start_Testtool contains an attempt to wait
for testtool to become usable. This is done by waiting for
the first test tool device to come online. This was done with
assumption that further testtool devices will come online
very quickly after the first one.

However it turns out the test tool startup may take
considerable amount of time even after this first device
comes online. Thus the "the remaining testtool devices come
online quickly" assumption is not valid and overlapping this
time consuming operation with the device configuration test
case in the scaling test suite causes the test case to be
blocked waiting for testtool to supply the next device,
destroying the validity of its results.

To fix this amend the "wait for testtool to boot" action
to make sure that all testtool devices are online and then
move the testtool startup into the first test case in the
suite as it now can fail.

Change-Id: Ie883d375e95e51d78c8343133182c644bde6e1df
Signed-off-by: Jozef Behran <jbehran@cisco.com>