Adding eEM1 and eEM2 into L1 menu for Heavy Ion runs

Two new phase-I low-threshold eEM items, i.e. eEM1 and eEM2, are introduced in athena:23.0 discussion following in ATR-26979.

Tagging menu coordinator @lidiaz and @astruebi for checking the implementation

Also tagging HI trigger menu coordinators @jkremer and @asmaga