replace MARKTYPES_MAP with markType methods in each mark namespace
replace MARKTYPES_MAP with markType methods in each mark namespace

vega/vega-lite,uwdata/vega-lite,uwdata/vega-lite,vega/vega-lite,vega/vega-lite,uwdata/vega-lite,vega/vega-lite,uwdata/vega-lite,vega/vega-lite,uwdata/vega-lite