[Bug] Select-all causes all blocks except the original block to be selected

Replication steps:

- Move cursor to a block in a document with many blocks
- Press Cmd-A - the text in the current block is selected
- Press Cmd-A - all blocks are selected
- Press Cmd-A - now all blocks, *except the original block*, are selected

Edit: Here is one possible resolution. It removes the ability to press Cmd-A multiple times to toggle selection, which seems acceptable to me: https://github.com/raykyri/editor.js/commit/7129f8c93c70289c31c8b110622700a5e5a712d9