Make rate-limit-configurable

GPU: Unify cluster rejection logic in central inline function

HistogramRegistry: improve output sorting (AliceO2Group#4684)

- improve code doing the sorting
- place subdirectories always at the top

Co-authored-by: Mario Krüger <mario.kruger@cern.ch>

README updated

Allow skipping MC in MID ditis reader and do this in DigitsToRawWorkflow

Allow skipping MC in MID ditis reader and do this in DigitsToRawWorkflow

Improve memory usage debug output

DPL: fix parsing of inputspec metadata (AliceO2Group#4660)

DataFormats: make readability-braces-around-statements happy

PWGHF: Reduce size of track index skim table. (AliceO2Group#4651)

- Remove collision column.
- Reduce size of the flag column type.