Convert string of type/eltype to Type itself

Describe is running on a sample of the full dataset. Some of the columns are sparse and therefore empty, or the source is using numbers for chars and other such stupidities which require manual adjustment.

Like I mentioned, I managed a solution so this topic is more of a “we should cover this case if we’re serious about beating Python” bin. I have a New topic in usage regarding my current travails with JuliaDB which is my immediate concern.