Add new block: Form

[Awilum]

Block: Form
Form block is a wrapper for any other blocks, and may handle user input.

- type: Form
  properties:
    id: # Form ID 
    name: # Form name
    method: # Form method, post or get, default is post
    class: # Form class
    style: # Form style array
    data: # Form data array
    events: # Form events array

Epic: #1