Visualizer Bug

[Dammshine]

1. When execute empty C file, it gives an error. Which is fine, however after that the visualize debugger no render render node.
2. Annotation's dropdown not "smoothly transition" if there's a sub-dropdown opened up, in general if the tab is not open then the whole whole program wouldn't recognize. Sol 1, implement a mechanism to check if annotation provides not start simulation before it's done, Sol 2, always run a default annotation in background.