[FEATURE] It is not so practical to enter a data type

[HansMarcus01]

To declare a precision and accuracy, i need click on three dots but this is tedious.

To avoid this, I propose that each time a string or numeric data type is selected, there is the possibility of configuring its length (precision and accuracy for numeric types) in a more direct way.

[lethalSopaper]

This is issued in #64.