This reduces code duplication and makes it significantly easier to make
changes to the text cursor without having to individually modify several
files.

fixes #94828

* untitled - change mode when found in paste data

* do not update mode for readonly editors

If a screen reader is attached and the default value is not set we shuold automatically increase the page size to 1000 for a better experience

fixes #85833

Fixes #83150: Handle case where the mouse is hitting the textarea when the textarea is rendered at the cursor

Fixes #27801: Make the textarea use a proper font size, line height and height to help with the positioning of input pop-ups

Readonly helps out with TS's type guards and is also a good best practice. Specifically, readonly strings/numbers have their literal type instead of a generic `string` | `number` type, which can help catch dead code and some common programming mistakes

The underlying cause is the TextArea element is missing the readonly attribute.
This change applies the readonly attribute when the editor is created or the configuration changes to editor.readOnly === true.

fixes #7394