Make editor accessible💡

Currently the editor is not accessible for screen readers because:

1. It does not provide accessible names for interative elements.
2. It relies on non-iteractive elements for interaction.

Proposed solution:

1. Add accessible names to interactive elements via `aria-label` attribute or visually hidden text.
2. Add `role="button"` attribute to all interactive elements or (better) use `button` tag instead of `div`.
3. Add `aria-hidden="true"` and `focusable="false"` to SVG icons.