Block Saver with sanitizer

Hi,

Seems like the `block.save` doesn't sanitize the block data like the [editor.saver.save](https://github.com/codex-team/editor.js/blob/44c29dd645a03ab9b91e6f16f8249055be760b34/src/components/modules/saver.ts#L40) does.

What is the reason for not doing a sanitize on the block save?
Could you also sanitize the data on save or expose this `sanitizeBlocks` and sanitizer config of the block tool on `sanitize` and `block` apis respectively, to provide a way to sanitize it ourselves?

(Willing to contribute if needed).

Thanks.