Mixed types for VLookup/HLookup

[OssianEPPlus]

Excel appears to have limited support for mixed string and number types in a single column:

As mentioned in #1755 Excel's support for this seems limited. It doesn't work at all in reverse order for example.
A test and comment was left in code in #1764

Epplus in its current solution does not compare strings and numbers other than that it considers them not-equal in the comparer returning -1. This breaks the binary search in difficult to predict ways.

This could be handled better via splitting ranges/entries somehow and only checking one depending on if the lookup_value is a string literal or a number.

The question is, how should EPPLUS behave compared to Excel in this? Do we implement buggy behaviour? Do we do our own fully functional solution? Do we limit scope to non-mixed types?

Investigation and internal discussion is required.