I made a somewhat silly assumption when writing the group_manager, that
all Test classes would use list arguments. While this assumption is true
for tests that require an entire command as their first argument it
isn't true of GleanTest, where only the name of the subtest is passed.
In this case it will be a string, and if a name isn't passed as well
then name will end up being " ".join()'ed, ie, "api" -> "a p i".

This patch adds support to the group_manager to support this feature.

I considered two other approaches here. The first was to say screw
correctness, and just add a duplicate name to the handful of tests that
use the group_manager. The second was to change GleanTest to take a 1
element list. Both of these had downsides that I couldn't justify.

This fixes a handful of glean tests that use the group_manager (fbo,
api2, etc)

Signed-off-by: Dylan Baker <dylanx.c.baker@intel.com>
Tested-by: Jose Fonseca <jfonseca@vmware.com>
Tested-by: Michel Dänzer <michel.daenzer@amd.com>