Local adjustments - Log encoding - Ciecam16 ContrastJ - contrastQ - contrast threshold (#6169)

* Added contrast threshold Log encoding

* Improve contrast threshold

* Chanhe tooltip

* Change sign threshold when contrast negative

* Another change threshold with contrast Q and J

rtengine/procevents.h

@@ -1064,6 +1064,7 @@ enum ProcEventCode {
     Evlocallabdivgr = 1038,
     EvLocallabSpotavoidrad = 1039,
     EvLocallabSpotavoidmun = 1040,
+    Evlocallabcontthres = 1041,
     NUMOFEVENTS
 };