print more column metadata

[behrica]

currently we print:

#tech.v3.dataset.column<keyword>[150]
:species
[:setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa, :setosa...]

while I would like to see as well other machine learning related flags printed:

• categorical?
• inference target?
• prediction
• the categorical map