web: limit number of states in output to prevent unresponsive browser

[m4lvin]

When generating a knowledge structure with a lot of states a query such as WHERE? Top will lead to a huge list in the output that can take very long to render and make the browser unresponsive or even crash while rendering too much MathJax.

It might thus be good to set a limit of the maximum number of states listed, similar to how we do not draw Kripke models for more than 32 possible worlds:

SMCDEL/exec/smcdel-web.hs

Lines 80 to 81 in 4217df5

	if numberOfStates mykns > 32
	then html . TL.pack $ "Sorry, I will not draw " ++ show (numberOfStates mykns) ++ " states!"