Although a range search might make sense for some text columns, the nature of text fields is that their content can be extremely varied with patterns that don't always follow a simple sequence.
The existing ability to use wildcards, and if needed, full-text search, is still a good and flexible solution.
For more details on searching text columns see: Custom Text Search
For this reason I am going to skip this feature request. Please comment below if you think of reasons to pursue this further.