wp.blocks.registerBlockStyle( 'core/video', {
    name: 'bb-background',
    label: 'Background',
} );
wp.blocks.registerBlockStyle( 'core/image', {
    name: 'bb-block-bg-fit',
    label: 'Fit Background',
} );
wp.blocks.registerBlockStyle( 'core/image', {
    name: 'bb-block-bg-full',
    label: 'Full Background',
} );