`combineVendFileInfo` sub-setting issue

[tactless2004]

Problem

combineVendFileInfo is supposed to combine the isodat/dxf data with its metadata (file_id, identifier1, analysis, preparation, etc.), however it currently does this in a very fragile manner.

Proposed Solution

Grab each column in by name, and re-name columns by a map (new-name only gets applied to column with old-name) rather than positionally by index. Also, fix sub-setting such that only the requested columns are returned and if those columns do not exist a specific, informative error is returned.

[tactless2004]

The solution for this issue creating subsequent issues.

My key assumption was if a requested column does not exist, do not create it and throw an error, but that is not the intended behavior. If a requested column does not exist, it should be created and filled with NAs. This will need to be fixed before the issue can be closed.