Implement inline showing of videos via ipython.display

[balintlaczko]

Similar to #121. Here is an example. It could also solve the problem of #100.

[balintlaczko]

Update: the method linked above is outdated, there seems to be IPython.display.Video as a better approach.

[balintlaczko]

Implemented with IPython.display.Video. Some people say it won't work in Colab, so that's yet to be tested. It won't work in VS Code.