WIP add water and ammonia loss fragment peak annotations and spectral library

[trishorts]

water and ammonia loss peaks are prevalent in tandem mass spectra. However, including them during the search phase with primary ions leads to a loss in sensitivity. But, once the peptide ID is determined, we can go back and label fragments emanating from water and ammonia loss because these don't contribute to the peptide match score. These peaks can also be added to the library spectrum, which should improve the sensitivity of spectral similarity calculations.