Expand mass Import file types

Another feature request here, based on my mass import question. Currently there is ability to import gpx / json / geojson. What I'm wondering is whether this could be expanded. I'm wholly unfamiliar with D as a language (mostly R and Python are my wheelhouse, & aspiring to learn Rust), so I can't comment on available libraries with any useful authority. But from a high level perspective, within GIS, ESRI shapefile is still dominant (though note shapefile must die!), but being superceded by much more robust geopackage format among geospatial data scientists, there is also compatibility baked in here w/ Postgres databases with PostGIS extensions given the mutual conformity to OGC standards.

In terms of plain text, csv is the old favourite and still widely used though, happily superceded by GeoJSON and TopoJSON as far as I can tell.

If is, of course, possible to convert anything to GeoJSON using GDAL on the command line, and this is what I'll be doing in the meantime. But for wide usage among geospatial communities I think lacking geopackage will be a problem long term.