HPCC-9084 Delimit JSON across multiple Roxie ouputs

New pull request targeting closedown-4.0.x from previous pull request:

https://github.com/hpcc-systems/HPCC-Platform/pull/4195

Roxie JSON/HTTP is not being delimited across multiple outputs. This is a bug in the new
feature added to 4.0 and ideally this fix will be merged into the next release candidate.

Signed-off-by: Anthony Fishbeck Anthony.Fishbeck@lexisnexis.com