add option to discard event with energy cuts in germanium

[ManuelHu]

• Remove the unused analysis manager parameter from the output scheme constructors. It is still passed in in every invocation of its functions, as before
• Initialize output schemes at detector construction time. This is necessary to have their commands available to macro files
• Introduce RMGVOutputScheme::ShouldDiscardEvent() to be able to discard an event before any output action writes out their data
• Introduce RMGVOutputScheme::{StackingActionClassify,StackingActionNewStage}() to be able to hook into the RMGSTackingAction

fixes #47
fixes #41

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