This commit switches the 'test_Summary' unit test to use class ESmry
for inspecting the values output to disk by 'out::Summary'. As a
consequence, we are not able to verify units of measure for the
parameters, at least not for the time being. Moreover, class ESmry
exclusively uses the "i,j,k" sub-key for block-related parameters so
switch those to reference the IJK identifiers.
Finally, as class ESmry currently does not support reading separate
(multiple) summary files, switch the input decks to generate unified
output.
