Added L1_eEM15_EMPTY
Following the requests in ATR-27940
- Added L1_eEM15_EMPTY
- Moved noalg, larpsallem, and noalg_LArPEBNoise chains from L1_2eEM9_EMPTY to L1_eEM15_EMPTY
- Cloned all L1_2eEM9_EMPTY Physics chains to L1_eEM15_EMPTY
Following the requests in ATR-27940