Vcfstats

- Introduce enhancements (pwwang/vcfstats15)

- Use `plotnine` instead of `ggplot2` so no `R` is needed
- Add `figfmt` to generate different format of figures other than `png`

- Use lark-parser to parse formulas
- Add ggrepel in Dockerfile
- Use rich.table to print macros
- Allow python -m, avoid root logger configuration.

- Adopt lastest pyparam.