codeintel: Do not fall back to input range when it cannot be adjusted

Created by: efritz

When adjusting ranges from the commit for which we have a code intelligence index and the commit the user is browsing, we fall back to the original range when the adjustment fails. This happens to allows us to jump to a valid location, just in a slightly different commit, instead of omitting a partially correct result. However, this caused some weird behaviors to happen with Range queries in particular (see an example).

We now return only data in Ranges requests that we know to be translatable into the user's current viewing commit.