Insert measure in score with part and without title fails

3d131042e9

1. Create a score without title and with one instrument
2. Create a part for this instrument
3. Add quarter notes in the 3 first measures and select the second measure
4. Insert a measure

Expected result: a measure is inserted in the part between measure 1 and 2.
Actual result: a empty measure, without rest is inserted in a weird place in the part

Discussion: To find where the measure(base) should be inserted, we count the measures and rely on a measureBase index. Unfortunately, the index in the part can be different than the index in the score because of additional frames/boxes...