Implement loop reading input sequentially

This merge request implements the input synchronization

Following conversations with interested parties:

• Both the processing and validating parts should access the same data
• The loop block shall read the input before processing continues

Part of beat.core#85 (closed)

added critical enhancement labels

changed title from Implement loop read sequentially input to Implement loop reading input sequentially

changed the description

OK for this one as well.

merged

mentioned in commit a749c91c