Extract React Application as a Feature (#7441)

* Fix webpack config for react

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Introduce package for discovering html elements in unit tests

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Switch to using discovery of html elements from package

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Introduce competition for starting react application inside the Feature

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Move stuff in application start to earlier timeslot having no real need to be done so late

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Switch to using react application root feature being more friendly to extending

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Switch to using more familiar pattern of higher order components for wrapping react application

Co-authored-by: Mikko Aspiala <mikko.aspiala@gmail.com>

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Adapt to more familiar pattern for higher order components

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Rename feature for clarity

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

---------

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

packages/core/package.json

@@ -122,6 +122,7 @@
     "@hapi/subtext": "^7.1.0",
     "@k8slens/cluster-settings": "^6.5.0-alpha.1",
     "@k8slens/node-fetch": "^6.5.0-alpha.1",
+    "@k8slens/react-application": "^1.0.0-alpha.0",
     "@kubernetes/client-node": "^0.18.1",
     "@material-ui/styles": "^4.11.5",
     "@ogre-tools/fp": "^15.1.2",
@@ -190,6 +191,7 @@
   "devDependencies": {
     "@async-fn/jest": "1.6.4",
     "@k8slens/messaging-fake-bridge": "^1.0.0-alpha.1",
+    "@k8slens/react-testing-library-discovery": "^1.0.0-alpha.0",
     "@material-ui/core": "^4.12.3",
     "@material-ui/icons": "^4.11.2",
     "@material-ui/lab": "^4.0.0-alpha.60",