Update Tab Behavior

### Details:
1. Type `- `
2. Press **tab**
3. Notice the whole line is indented
4. Add some text and press **tab**

As a result, the line will be indented again. Tab Indentation should only happen whenever the cursor is in the `[0, first non marking character)`: step 4 should not be indenting the whole line again.

Reproduce the behavior in the macOS editor using the four steps in the issue, then locate the entry point that handles Tab indentation. The change is complete when Tab indents only while the cursor is before the first non-marking character, and does not re-indent the whole line after text has been added.

Written by the indexing model from the issue text.