Added the Self Serve Data Model (#367)

* added recursion and inition decorators

* working version

* added todo comment and removed console.log

* Added Recursive add

* removed type requirement

* proper resolution of promises

* added custom element and base class

* Made selfServe standalone page

* Added custom renderer as async type

* Added overall defaults

* added inital open from data explorer

* removed landingpage

* added feature for self serve type

* renamed sqlx->example and added invalid type

* Added comments for Example

* removed unnecessary changes

* Resolved PR comments

Added tests
Moved onSubmt and initialize inside base class
Moved testExplorer to separate folder
made fields of SelfServe Class non static

* fixed lint errors

* fixed compilation errors

* Removed reactbinding changes

* renamed dropdown -> choice

* Added SelfServeComponent

* Addressed PR comments

* merged master

* added selfservetype.none for emulator and hosted experience

* fixed formatting errors

* Removed "any" type

* undid package.json changes

src/Explorer/Controls/FeaturePanel/FeaturePanelComponent.tsx

@@ -48,6 +48,7 @@ export const FeaturePanelComponent: React.FunctionComponent = () => {
     { key: "feature.hosteddataexplorerenabled", label: "Hosted Data Explorer (deprecated?)", value: "true" },
     { key: "feature.enablettl", label: "Enable TTL", value: "true" },
     { key: "feature.enablegallerypublish", label: "Enable Notebook Gallery Publishing", value: "true" },
+    { key: "feature.selfServeType", label: "Self serve feature", value: "sample" },
     {
       key: "feature.enableLinkInjection",
       label: "Enable Injecting Notebook Viewer Link into the first cell",