more testing
unit all FunctionScore things -  step1: move to same package and rename more general
make boost query builder a ScoreFunctionBuilder
make boost score parser a Score function parser and fix tests
support boost parameter for all custom score functions
custom score builder -> score function builder

also, support filters!
script score parser -> score function parser + legacy
format
fix test
rename
move mapping of string to function parser to separate class
new class for filtering and functions but with different format

also allows distance scoring etc