Vue main section overhaul (#2161)

* Separate browse object from conductor

* Main layout convert to flex; padding and overflow at leaf node

* Inspector converted to BEM - WIP

 - Properties pool upper level styles converted;
 - Grid mixins moved out of Inspector and into _mixins;

* Refinements to misc elements

- user-select: none on tree;
- :before and :after reset globally to use box-sizing: border-box;
- li reset globally;

* Styling for buttons and menus; add Create button

 - WIP

* Context and Create menus

 - WIP

* Add glyph backgrounds as data URIs

- For Create menu, items grid;
- Objects only;

* Create menu refinements

- Min/max height handling;
- Code cleanup;

* Main layout head styling; various sanding

- head layout refined;
- c-icon-button, c-button-set added;
- background glyph mixin refined;
- Antialiasing refined to increase icon sharpness;

* Fix SVG data URLs: encode # chars as %23

platform/commonUI/browse/res/templates/browse-object.html

@@ -66,5 +66,4 @@
             </mct-representation>
         </div>
     </div>
-    <mct-include key="'conductor'" class="abs holder flex-elem flex-fixed l-flex-row l-time-conductor-holder"></mct-include>
 </div>