Don't dim SCH_FIELDs when selecting them.

(They were only getting drawn on top of the selection shadow when
drawn by their parent symbol because LIB_FIELD was correctly
setting the view layers but SCH_FIELD was not.)

(cherry picked from commit 2300b0d2a3)

eeschema/sch_field.cpp

@@ -427,6 +427,21 @@ COLOR4D SCH_FIELD::GetFieldColor() const
 }
 
 
+void SCH_FIELD::ViewGetLayers( int aLayers[], int& aCount ) const
+{
+    aCount      = 2;
+
+    switch( m_id )
+    {
+    case REFERENCE_FIELD: aLayers[0] = LAYER_REFERENCEPART; break;
+    case VALUE_FIELD:     aLayers[0] = LAYER_VALUEPART;     break;
+    default:              aLayers[0] = LAYER_FIELDS;        break;
+    }
+
+    aLayers[1] = LAYER_SELECTION_SHADOWS;
+}
+
+
 EDA_ANGLE SCH_FIELD::GetDrawRotation() const
 {
     // Calculate the text orientation according to the symbol orientation.

eeschema/sch_field.h

@@ -144,6 +144,8 @@ public:
             m_lastResolvedColor = aField->m_lastResolvedColor;
     }
 
+    void ViewGetLayers( int aLayers[], int& aCount ) const override;
+
     /**
      * Adjusters to allow EDA_TEXT to draw/print/etc. text in absolute coords.
      */