Run handle_error for any exceptions raised in execute_context()

Run handle_error for any exceptions raised in execute_context()

Observing a SQLite connection/cursor being hung on
test_resultset -> PositionalTextTest -> test_dupe_col_obj.
this uses connectionless execution and the result object
fails to be constructed.  When that happens, there is no path
for the cursor or connection to be closed / released.
Recent changes with the exception assertions in #4849 seem to
be causing a cycle to last a little longer than usual which
is exposing this issue for one particular test on SQLite.

As we want to get rid of weakref cleanup, evaluate
why we dont have handle_dbapi_exception for this whole
block, as after_cursor_execute can raise, result construction
can raise, autocommit can raise, close can raise, there
does not seem to be a reason these things should be outside
of the block that gets cleaned up.

Fixes: #5182
Change-Id: I640ac55e8c5f39d287f779fbb5dc0ab727218ca3