Focus ipython terminal on startup

[bhoov]

(See this comment)

When starting an interactive session, automatically focus on the iPython terminal that is running Manim (like what happens when an error message occurs)

Right now, a new ipython terminal is silently created "behind" the active terminal window. To prevent confusion, let us automatically switch to this terminal on startup regardless of whether the terminal window is visible or hidden

[Splines]

related to #34

[Splines]

Do you still want this feature even with #33? There, we prevent confusion by showing an indefinite Starting Manim notification.

• Upon error, we could
  • stop the current progress notification (see Detect errors in Manim startup command #34)
  • and open the terminal (like already done when an error occurs while previewing code)
• We could additionally show a button See in terminal to the Starting Manim notification. This way, if users really want to see what is going on in the terminal, they can just click that button.

This workflow would favor the "terminal-free" approach.