QueryObjectModelImpl should execute queries as SessionOperation(s)

QueryObjectModelImpl doesn't leverage the SessionOperation closure approach (like the QueryImpl does).

Switching to this style of running a query yields some gains in speed (I ran 50 queries per test):

• #1. old style (no code change) avg was 14.26 ms
• #2. new style (as session operation) avg was 12.14 ms
• #3. new style (as session operation) avg was 6.44 ms
• #4. new style (as session operation) avg was 6.68 ms
• #5. old style (no code change) avg was 11.62 ms
• #6. old style (no code change) avg was 11.66 ms