[block-editor-utils] Allow users to add custom controls

[theodesp]

Description

block-editor-utils package should allow the users to add their own custom controls.

Acceptance Criteria

• package allows users to add their own custom control or mappings from type to control.
• Update documentation page at https://faustjs.org/tutorial/react-components-to-gutenberg-blocks

Technical Details

• Instead of hardcoding the mapping in code, we should use a wp-hooks filter to retrieve it. This allows users to add their own hooks and modify that mapping. See: https://github.com/wpengine/faustjs/blob/canary/packages/block-editor-utils/src/helpers/getControlFields.ts#L4-L11