HPCC-10240 Prevent a TABLE() aggregate being converted to a non aggregate

Switch to using a no_newaggregate much earlier in the tree normalizsation so
it will be treated as an aggregate - even if all fields are removed.

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-10240 Fix example following review feedback

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #5029 from ghalliday/issue10240

HPCC-10240 Prevent a TABLE() aggregate being converted to a non aggregate

Reviewed-By: Jamie Noss <james.noss@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>