[RTE]: improve errors handing

## Description
Sometimes we can get an error inside the RTE, for example, when a user inserts invalid content, unexpected actions, or for some other reason (a huge variety of actions). In this case, we often get a JS error from inside the RTE, and our default UUI ErrorHandling draws an ErrorPage, which shows instead of the RTE, and thus the user loses the data they entered. Moreover, not all errors are critical, and in some cases, the user can continue working with the RTE.

## Describe the solution you'd like
Improve the error handling mechanism, which will not lead to unmounting the component and ErrorPage:

- Explore the capabilities of Slate and Plate for error handling - https://github.com/ianstormtaylor/slate/pull/5407. We need to check if there is a way to catch the error and leave the editor working.
- Improve UX to show the user the error inside the RTE, without losing the entered data.