feat: Print nicer error messages

[sbernauer]

From
Error: StartVncServer { source: ReadFontFile { source: Os { code: 2, kind: NotFound, message: "No such file or directory" }, font_file: "212" } }
to

Error: Failed to start VNC server

Caused by these errors (recent errors listed first):
  1: Failed to read font from file 212
  2: No such file or directory (os error 2)