Incorporate query size to term size values from g:Profiler into EM generic output so it can be used to node size mapping

[risserlin]

In gprofiler general results there is a column called (Q *T)/T (Q=query size, T=Term size) that gives a good measure of query to term size that would be better to use when sizing nodes in the network.

Currently there is no column in generic format to store this value (but both bingo, david and great have this value in the output and are loaded when parsing those datasets).

We can get this value from gprofiler when calling gprofiler from R (It is not in the generic format exported from gprofiler GUI).

**Add node size attribute to generic format - column will be used to map directly to node size so even for users creating an EM from other programs can enter numeric value indicating relative size.