Recast "Gathering information about..." sections into a data mapping discussion

[ahouseholder]

This issue is prompted by:

Would it be possible though to give some indication on how hard it is to gather information about certain decision points?

Originally posted by @jeroenh in https://github.com/CERTCC/SSVC/issues/315#issuecomment-1767992071

I think so. Now that we've opened up the concept of data mapping in our documentation, we might want to reframe many of the "Gathering information about..." sections to be more focused on that data mapping process. And something akin to degree of difficulty would seem relevant in that context.

Originally posted by @ahouseholder in https://github.com/CERTCC/SSVC/issues/315#issuecomment-1771478693

[j---]

I'd like to submit that data mapping may be a separate step that after gathering information about a topic. Though knowing what data you could map to a decision certainly informs capability improvements in how information is gathered, so there is a loop. So it may make sense to merge the two concepts, but I don't think it's a reframing so much as an addition?