🔧 chore: use custom highlights api for text highlighting

### 🔧 Chore Description

_What needs to be done?_

We currently create extra span elements for the highlighting which modifies the dom. This means  we have to modify the dom again to do an accurate search.
The custom highlights api does not modify the dom!

https://developer.mozilla.org/en-US/docs/Web/API/CSS_Custom_Highlight_API