Enable casting PyObject's to primitives; provide type param info for py lists

[nbauernfeind]

Also did this for String/boolean/Boolean:

from deephaven import TableTools
x = ['0', '1', '42', None]
y = TableTools.emptyTable(1).update("X = (String)x[i % x.size()]")
print(y.getDefinition())

Note that after some discussion we preferred to NPE when casting to boolean and the value is a None. We also decided that a String cast should throw an exception if not already a String (instead of converting via PyObject::str).

Fixes #1009

[rcaudy]

Good change overall. Needs more testing, and maybe some cleanup in Param.