Add beatAML phosphoproteomics

[jjacobson95]

Extend the beatAML dataset with phosphoproteomics, mapped to phosphosite_id using the global phosphosites reference, mirroring the cNF phosphoproteomics pipeline.

• Source the beatAML phospho data; map sites to phosphosite_id.
• Produce beataml_phosphoproteomics.csv conforming to the Phosphoproteomics schema class.
• Depends on the phosphosites reference being available (Publish the phosphosites reference to Figshare #495).