TCT: added additional expressstream tests
This is the continuation of MR !39945 (merged), where one new expressstream TCT test was added using data18 as input and MT enabled.
This MR adds more copies of this test which uses different input LBs. Also the number of threads is updated to 8. These tests should replace the older version, i.e. test_expressstream_1_run276689_collisions.sh, test_expressstream_2_run276689_collisions.sh, ..., which will be disabled later.
Tagging @rmazini