api: Add is_tid parameter to cgroup_get_cg_type()

api: Add is_tid parameter to cgroup_get_cg_type()

Add new parameter bool is_tid to cgroup_get_cg_type(), this parameter
gets set, when called from cgroup_attach_thread_tid() path. When set and
cgroup.type is 'domain threaded', it returns 'cgroup.threads' instead of
'cgroup.procs'.

Fixes: https://github.com/libcgroup/libcgroup/issues/441
Reported-by: Adriaan Schmidt <adriaan.schmidt@siemens.com>
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>