Add create seed/example project and generate ui schema (#3)

* Add create seed project function to theia and vscode
* Add create example project function to theia and vscode
* Add generate UI schema function to theia and vscode

Author: TheZoker

package-lock.json

@@ -2,13 +2,11 @@
   "scripts": {
     "lerna": "lerna",
     "postinstall": "npm run lernabootstrap && npm run lernainstall",
-    "lernainstall": "lerna exec --no-bail --npm-ci-mode -- npm run postinstall",
+    "lernainstall": "lerna exec --no-bail --npm-ci-mode -- npm run custominstall",
     "lernabootstrap": "lerna bootstrap --npm-ci-mode --ignore-scripts",
     "compile": "lerna run build"
   },
   "devDependencies": {
-    "@theia/plugin": "^0.4.0-next.8c668434",
-    "@theia/plugin-packager": "0.0.1-1539891078",
     "@types/node": "^10.12.10",
     "lerna": "^3.4.3",
     "rimraf": "2.6.2",