Restructure extension apis (#1101)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

extensions/example-extension/page.tsx

@@ -1,10 +1,10 @@
-import { Button, Icon, IconProps, LensRendererExtension } from "@lens/ui-extensions";
+import { Component, LensRendererExtension } from "@lens/ui-extensions";
 import { CoffeeDoodle } from "react-open-doodles";
 import path from "path";
 import React from "react"
 
-export function ExtensionIcon(props: IconProps) {
-  return <Icon {...props} material="pages" tooltip={path.basename(__filename)}/>
+export function ExtensionIcon(props: Component.IconProps) {
+  return <Component.Icon {...props} material="pages" tooltip={path.basename(__filename)}/>
 }
 
 export class ExtensionPage extends React.Component<{ extension: LensRendererExtension }> {
@@ -22,7 +22,7 @@ export class ExtensionPage extends React.Component<{ extension: LensRendererExte
         <div style={doodleStyle}><CoffeeDoodle accent="#3d90ce" /></div>
         <p>Hello from Example extension!</p>
         <p>File: <i>{__filename}</i></p>
-        <Button accent label="Deactivate" onClick={this.deactivate}/>
+        <Component.Button accent label="Deactivate" onClick={this.deactivate}/>
       </div>
     )
   }

extensions/example-extension/renderer.ts

@@ -1,4 +1,4 @@
-import { DynamicPageType, LensRendererExtension, PageRegistry } from "@lens/ui-extensions";
+import { Registry, LensRendererExtension } from "@lens/ui-extensions";
 import { examplePage, ExtensionIcon } from "./page"
 
 export default class ExampleExtension extends LensRendererExtension {
@@ -6,10 +6,10 @@ export default class ExampleExtension extends LensRendererExtension {
     console.log('EXAMPLE EXTENSION RENDERER: ACTIVATED', this.getMeta());
   }
 
-  registerPages(registry: PageRegistry) {
+  registerPages(registry: Registry.PageRegistry) {
     this.disposers.push(
       registry.add({
-        type: DynamicPageType.CLUSTER,
+        type: Registry.DynamicPageType.CLUSTER,
         path: "/extension-example",
         title: "Example Extension",
         components: {