Rebuild application in React

[erksch]

As I wanted to add more features to the viewer, I found using the standard way of doing things with javascript DOM manipulation tedious as ever. Since I use React on a daily bases in various projects I decided to reimplement everything with React and the awesome library react-threejs-fiber for the rendering code. This also allowed me to give the app a facelift for stuff like loading segments and error handling, since state is much easier to handle.

With the react rebuild come to new features: support for 3D object detection and semantic segmentation. You can specify a server where the current frame is sent to, the server should respond with bounding boxes for 3D object detection) or point labels for segmentation. The viewer then automatically displays the result!

This pull request is still very work in progress, it currently lacks:

• Updated README how build and use the react app
• Template code for servers that run segmentation or object detection and communicate with the viewer
• Polish for loading indications and error messages
• Polish for styling components and remove all inline styling

[Nuri-benbarka]

@erksch
now only the first frame in the segment is loading.

[erksch]

@Nuri-benbarka As I can't make a commit right now, you can fix the problem by removing the two comments in useWebsocket.ts. The lines commented out are responsible for continuous fetching.
Line 83 and 128.