Trigger 'BiomassRemovalEvents' based on crop phenological stage

[novel-ecosystem]

Describe the new feature

Simulating crop management for silage in APSIM requires precise biomass removal at certain phenological stages. Currently, this involves complex scripting for biomass extraction and soil organic matter addition. The 'BiomassRemovalEvents' model could be used to simplify this process, however it lacks the functionality to initiate events based on crop phenological stages. A configuration option could be added to the 'BiomassRemovalEvents' model for users to specify phenological stages as triggers for biomass removal. This would enhance APSIM's usability for simulating crop management practices that depend on growth stages.