[Meta] Class component refactoring

## Description

> [!IMPORTANT]
> **If you are a community contributor.** We only accept community PRs for sub-issues tagged as `help-wanted`. All other PRs will be closed.

EUI has still a lot of class components. To ensure a common implementation and reduce maintenance friction, we should refactor them to function components.

For some of them, refactoring them might potentially also resolve other related issues (e.g. related to Strict mode support).

**See comments for more details.**