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

---------

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

src/Main.tsx

@@ -1,5 +1,5 @@
 // CSS Dependencies
-import { initializeIcons } from "@fluentui/react";
+import { initializeIcons, loadTheme } from "@fluentui/react";
 import { QuickstartCarousel } from "Explorer/Quickstart/QuickstartCarousel";
 import { MongoQuickstartTutorial } from "Explorer/Quickstart/Tutorials/MongoQuickstartTutorial";
 import { SQLQuickstartTutorial } from "Explorer/Quickstart/Tutorials/SQLQuickstartTutorial";
@@ -26,6 +26,8 @@ import "../less/TableStyles/CustomizeColumns.less";
 import "../less/TableStyles/EntityEditor.less";
 import "../less/TableStyles/fulldatatables.less";
 import "../less/TableStyles/queryBuilder.less";
+import * as StyleConstants from "./Common/StyleConstants";
+import { configContext, Platform } from "ConfigContext";
 import "../less/documentDB.less";
 import "../less/forms.less";
 import "../less/infobox.less";
@@ -57,6 +59,7 @@ import "./Libs/jquery";
 import "./Shared/appInsights";
 import { useConfig } from "./hooks/useConfig";
 import { useKnockoutExplorer } from "./hooks/useKnockoutExplorer";
+import { appThemeFabric } from "./Platform/Fabric/FabricTheme";
 
 initializeIcons();
 
@@ -67,6 +70,10 @@ const App: React.FunctionComponent = () => {
   const shouldShowModal = useQueryCopilot((state) => state.showFeedbackModal);
 
   const config = useConfig();
+  if (config?.platform === Platform.Fabric) {
+    loadTheme(appThemeFabric);
+  }
+  StyleConstants.updateStyles();
   const explorer = useKnockoutExplorer(config?.platform);
 
   const toggleLeftPaneExpanded = () => {
@@ -84,6 +91,7 @@ const App: React.FunctionComponent = () => {
 
   return (
     <div className="flexContainer" aria-hidden="false">
+      <LoadFabricOverrides />
       <div id="divExplorer" className="flexContainer hideOverflows">
         <div id="freeTierTeachingBubble"> </div>
         {/* Main Command Bar - Start */}
@@ -135,6 +143,19 @@ const App: React.FunctionComponent = () => {
 
 ReactDOM.render(<App />, document.body);
 
+function LoadFabricOverrides(): JSX.Element {
+  if (configContext.platform === Platform.Fabric) {
+    const FabricStyle = React.lazy(() => import("./Platform/Fabric/FabricPlatform"));
+    return (
+      <React.Suspense fallback={<div></div>}>
+        <FabricStyle />
+      </React.Suspense>
+    );
+  } else {
+    return <></>;
+  }
+}
+
 function LoadingExplorer(): JSX.Element {
   return (
     <div className="splashLoaderContainer">