Make pretty-printing of graphs available to codeql query run

codeql test run has a nice pretty-printer for graph queries (i.e. for the PrintIR query for cpp).
It would be great to have the option to run queries using codeql query run and then get the output pretty-printed.
The results of PrintIR.ql are otherwise not that helpful.

Start by comparing how `codeql test run` pretty-prints graph-query results with the output from `codeql query run`, using the C++ `PrintIR.ql` example mentioned in the issue. Done means `codeql query run` offers an option that produces the same useful pretty-printed output for graph queries.

Scritto dal modello di indicizzazione a partire dal testo della issue.