Work on refactoring measurements out of Lesion Tracker package

- Removed AssociatedStudies Collection
- Measurement API is generated from configuration files
- Data exchange methods are defined in configuration

Packages/ohif-viewerbase/client/components/viewer/toolbarSectionButton/toolbarSectionButton.styl

@@ -0,0 +1,61 @@
+@import "{design}/app"
+
+.toolbarSectionButton
+  display: inline-block
+  theme('color', '$defaultColor')
+  theme('fill', '$defaultColor')
+  theme('stroke', '$defaultColor')
+  min-width: 30px
+  cursor: pointer
+  text-align: center
+
+  &.disabled
+    opacity: 0.5
+    cursor: not-allowed
+    
+    &:hover 
+      i,
+      .buttonLabel
+        theme('color', '$textSecondaryColor')
+
+  .buttonLabel
+    theme('color', '$textSecondaryColor')
+    font-size: 12px
+    font-weight: 500
+
+  .svgContainer
+    margin: 0 auto
+    text-align: center
+    
+    i
+      theme('color', '$textSecondaryColor')
+      font-size: 18px
+      line-height: 30px
+
+  svg
+    background-color: transparent
+    margin: 2px
+    width: 21px
+    height: 21px
+
+  &:hover
+    .buttonLabel
+      theme('color', '$hoverColor')
+
+    svg
+      theme('fill', '$hoverColor')
+      theme('stroke', '$hoverColor')
+      
+    i
+      theme('color', '$hoverColor')
+
+  &:active, &.active
+    .buttonLabel
+      theme('color', '$activeColor')
+
+    svg
+      theme('fill', '$activeColor')
+      theme('stroke', '$activeColor')
+      
+    i
+      theme('color', '$activeColor')