Show warning and error messages during variable transfer

[BoPeng]

sos-r/src/sos_r/kernel.py

Line 396 in b2edd5b

self.sos_kernel.run_cell(

Currently sos-r uses run_cell function to execute statement for variable assignment. With the silent=True parameter nothing is displayed even if there were warning and error messages.

It is worthwhile to investigate the use of get_response function to execute the statement, capture and display the warning and error messages.

A good example to trigger the warning is from #24 for out-of-range integers.