[FEATURE REQUEST] options page api for block development

[ivanjeremic]

When creating blocks for Gutenberg we can add block settings to the block pretty easily but there are often cases where you would like to have some global settings which are set once and are applied to all instances of that block, I would like to have besides the edit.js & save.js also an option.js where we can render the options page, also have in the block.json options to define the name of the menu item and where it will be.