These dummies do not exist in SWTOR. However it is very easy to do something similar:

Have a duell between a healer and the DD that needs the DPS rotation optimization. Heal the healer permanently and the DD attacks. That way I optimized all my DD and Healer rotations.
Another way is to test second boss and bonus boss in BT. Both can be kited and enrage timer will be the testing criteria. Please note that 2nd boss at first pull has 2 extra adds - so it is not comparable to a pull when adds are not there anymore. Later I used HK-47 in false emporer for DPS tests.