Initial Fabric support (#1607)

* Add Platform.Fabric to run in context of Fabric

* Use separate StyleConstants

We want to have more flexibility with Styles at runtime
but Constants depend on ConfigContext and therefore
get loaded very early at startup.

* Add Fabric specific styles and Fluent theme

documentDBFabric.less contains all styles for Fabric.
We use React.lazy to import them conditionally at
runtime preventing webpack from preprocessing
them into main.css.

* Restyle CommandBar for Fabric
with more roundness and native colors.

* Disable Notebooks when running in Fabric

* Disable Synapse and Scripts commands for Fabric

* Fix code formatting issues

* Fetch encrypted token from sessionStorage for fabric platform

* Fix Tabs style

* Dark refresh icons for Fabric

* Use new ResourceTree2 for Fabric

* Fluent tree should have a fixed width
otherwise the action buttons jump around on hover.

* Disable remaining Script actions in Fabric

* Revert accidentally committed change
which broke a test

* Fix cross-origin error second try

* Adjust @FabrixBoxMargin css

* Hide Database Scale node on Fabric

* Remove all Collection child nodes on Fabric

* Add a comment about why we need FabricPlatform.tsx

* Fix equality checks

* Fix more Colors for Fabric

* Switch resource tree to "medium" size

* Fix formatting again

* Fix formatting again

* Disable no-var-requires error on some intended var import.

* Increase memory limit for build

* Use standard Segoe UI font for Fabric

* Improve Tabs design for Fabric

* Fix active Tab style bug in Portal
introduced with 39a7765aef

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Co-authored-by: Laurent Nguyen <laurent.nguyen@microsoft.com>

src/Explorer/ContextMenuButtonFactory.tsx

@@ -18,6 +18,7 @@ import * as ViewModels from "../Contracts/ViewModels";
 import { userContext } from "../UserContext";
 import { getCollectionName, getDatabaseName } from "../Utils/APITypeUtils";
 import { useSidePanel } from "../hooks/useSidePanel";
+import { Platform, configContext } from "./../ConfigContext";
 import { TreeNodeMenuItem } from "./Controls/TreeComponent/TreeComponent";
 import Explorer from "./Explorer";
 import { useNotebook } from "./Notebook/useNotebook";
@@ -99,7 +100,10 @@ export const createCollectionContextMenuButton = (
     });
   }
 
-  if (userContext.apiType === "SQL" || userContext.apiType === "Gremlin") {
+  if (
+    configContext.platform !== Platform.Fabric &&
+    (userContext.apiType === "SQL" || userContext.apiType === "Gremlin")
+  ) {
     items.push({
       iconSrc: AddStoredProcedureIcon,
       onClick: () => {