Add "Inputfield Type" option to FieldtypeText

[Toutouwai]

Short description of the enhancement

The "Inputfield Type" option for FieldtypeTextarea is really handy when you want to create a custom inputfield module for use with FieldtypeTextarea. You only need the custom inputfield module to extend InputfieldTextarea and it becomes available for selection in the settings of textarea fields.

This request is for a similar option to be available for FieldtypeText. This would make it easier when you want a custom inputfield for use with FieldtypeText. Sometimes you don't need the extra length provided by a textarea fieldtype and don't want to have to create a custom fieldtype module to go with the inputfield module.