Suggestion: Enhance the Grid View

[lars18th]

Hi @EricBerendsen ,

I have some suggestions for the Grid View:

• First idea is to grey some pids. Or make them as the background colour. What I want is to see only in colours specific pids (mainly the audio and video pids of one service).
• The second idea is a method to print the timestamp marks in relation with the packets. For example, you print at the left the timestamp of the first PUSI packet of the LINE, and the line continues with a fixed size, based on some time slace (5,10,20,35,40ms, etc.)

The objective is to use this "view" to check more visualy if the muxing is done correctly.

I hope you want to consider this. Thank you for this very good project.