Use `--type` to restrict `--show-importable-formats` output

It’s great that qiime tools import can display the importable types and importable formats, but it can be hard to figure out which formats go with which types. A (potentially) simple change would be to limit the output of qiime tools import --show-importable-formats based on --type, so that only the importable formats for the user-selected type are shown. Another option would be to show a dict-like output of type --> format such as

FeatureTable[Frequency] => (BIOMV210Format, BIOMV100Format, ...)
FeatureData[Taxonomy] => (TSVTaxonomyDirectoryFormat, TSVTaxonomyFormat, ...)

Hi @nick-youngblut! This would be a really nice improvement, I created an issue to track progress. I don’t have an ETA but we’ll follow up here when it’s available in a release!