Add summarised by location type tracks

[iromeo]

Add summarised by location type tracks. E.g. for additive bigWig data (peaks) we can summarise peaks not by fixed bins, but by CCI, promoters, ChromHMM states. I suggest to implement it like Arithmetic tracks

[iromeo]

Supported for BED and CGIs, GTF support not implemented.

GTF support is important, because it's easy to generate custom GTF-based annotations from GTF genes annotations + modify to leave promoters, gene body, utrs, etc.