Search ordered by macrogenesis shows NaN for text in position hover

[gerritbruening]

When I search for https://dev.faustedition.net/search?q=Sehnen+AND+Gebein&order=genesis and hover over "Text", "NaN" appears. I presume that this means "Not a Number".
A user objects that this use of the expression is incorrect, since the context (a value that is undefined or unrepresentable) is lacking here.

[thvitt]

This hover shows the actual value of the ordering criterion – for the macrogenesis view, this is the position in the global ordering, which doesn’t exist for the text.

The number is just there for debugging purposes, maybe we can remove it altogether