ImGui Styling

[rfmineguy]

At some point we'll want to restyle ImGui to look a little more customized and look like a modern application.

Some imgui styling examples: ocornut/imgui#707

Themes I particularly like
ocornut/imgui#707 (comment)

GUI Design Link
https://www.figma.com/design/lpRrCPuqiM71xXQldEXnKi/LLDB-Frontend-GUI-Design?node-id=0-1&t=3wXUvuPBPdWq1gnn-1

[rfmineguy]

File Hierarchy

• Add icons next to files and folders
• Decrease indentation for the ImGUI tree view

[ZeunO8]

File Hierarchy

• Add icons next to files and folders[ ] Decrease indentation for the ImGUI tree view

looking really good as of #45 however you may wish to support more TreeNodeTypes before making this as complete