Fixes mac scheduler 2019 w13

Several fixes to have a better uplink scheduling.

The main identified problem was that retransmissions and new transmissions were sometimes done in the same RBs.

Some other problems have been fixed as well.

This is not the end of the story.

OAI eNb-CI build (772): Some Changed files in Merge Request DO NOT follow OAI Formatting Rules

OAI eNb-CI build (772): failed (https://open5glab.eurecom.fr:8083/jenkins/job/eNb-CI/772/)

mentioned in merge request !570 (merged)

merged