Fix parallel scans

Closes #948 (closed), #1083 (closed)

Here is a fix of the data watcher (redis client) when using parallel scans.

Data from one was able to be copied into the other one when it was needed to process the data received from the 2 at the same triggered event.

"0d" channels was impacted, and maybe images and MCAs.

This MR

• Fix the issue
• Add specific unittests