Improve tabulator expansion

### Description

If you press tabulator in value of text variables and enable expanding tab to spaces in Options -> Editor -> Formatting -> ... enable "Expand Tabs to Spaces" then number of spaces is not a same as for normal indention. That is probably bug, but I prefer to be there in "Option formatting" one more option to use escape sequence for tabulator if context enable.

### Use case/motivation

It is even clear and more readable.

### Related issues

_No response_

### Are you willing to submit a pull request?

No

Start in NetBeans at Options → Editor → Formatting and reproduce tab insertion in a text variable with “Expand Tabs to Spaces” enabled, comparing it with normal indentation. Trace the editor formatting behavior and clarify whether the goal is matching indentation width, an escape-sequence option, or both; done means the selected behavior is consistent and covered by an appropriate editor test.

Written by the indexing model from the issue text.