feat: ExpandDateTime convenience (datetime components)

[IndexSeek]

Closes #14, this is a recreation of #15, which I will close tomorrow.

The test has been updated as well. This is how I have been using it to try this out, similar to the previous PR.

from ibis.interactive import *
import ibisml as ml

con = ibis.duckdb.connect()

t = con.sql("select get_current_timestamp() AS datetime")
step = ml.ExpandDateTime("datetime")
transform = step.fit(t, ml.core.Metadata())
res = transform.transform(t)
res

When no literal values are passed to the components on the return, all columns except second and millisecond are chosen.

[jcrist]

Thanks!