Feature: fake selection improvement

## Description
Current implementation of `SelectionAlwaysOnDisplay` is not good, infact its worst, only a background color is applied to the fake selection but if certain text is having background color then selection gets skipped (selection is not visible) for that part of text

Either it should be configurable with background color and text color or something better

Locate the implementation and usage of SelectionAlwaysOnDisplay, then reproduce the reported case with text that already has a background color. Read the surrounding selection-rendering behavior and existing tests, if present. Done should mean the fake selection remains visible over such text and the chosen behavior is clearly specified and verified.

Written by the indexing model from the issue text.