Add const to many places

This follows !301 in core

include/gnss/processor/processor_gnss_fix.h

@@ -69,13 +69,13 @@ class ProcessorGnssFix : public ProcessorBase
          *
          * Returns true if processCapture() should be called after the provided capture arrived.
          */
-        virtual bool triggerInCapture(CaptureBasePtr) override;
+        virtual bool triggerInCapture(CaptureBasePtr) const override;
 
         /** \brief trigger in key-frame
          *
          * The ProcessorTracker only processes incoming captures, then it returns false.
          */
-        virtual bool triggerInKeyFrame(FrameBasePtr _keyframe_ptr, const Scalar& _time_tolerance) override {return false;}
+        virtual bool triggerInKeyFrame(FrameBasePtr _keyframe_ptr, const Scalar& _time_tolerance) const override {return false;}
 
         /** \brief store key frame
         *
@@ -89,7 +89,7 @@ class ProcessorGnssFix : public ProcessorBase
         */
         virtual bool storeCapture(CaptureBasePtr);
 
-        virtual bool voteForKeyFrame() override;
+        virtual bool voteForKeyFrame() const override;
 
     private:
         FactorBasePtr emplaceFactor(FeatureBasePtr _ftr_ptr);
@@ -100,7 +100,7 @@ class ProcessorGnssFix : public ProcessorBase
 
 };
 
-inline bool ProcessorGnssFix::triggerInCapture(CaptureBasePtr)
+inline bool ProcessorGnssFix::triggerInCapture(CaptureBasePtr) const
 {
     return true;
 }