use aggregated parameter object

[CXwudi]

instead of thinking about what parameters does each method need, just uniformly make methods receive and output a giant parameter object only. Each module will have their own parameter object, and it contains anythings needed to process one data through the entire batch processing procedure

[CXwudi]

such parameters will be included in a class is called VSongContent, it also two fields: label and parameter.
label contains everything in #2, parameter is the aggregated parameter object

[CXwudi]

parameter in kotlin should implement as a data class with each field is var fieldName: Type? = null (reason: can isolate as much as processing logic away from RecordReader)

[CXwudi]

done as #21 done