Extend/editable components

Composer uses .json files on the server anyways so it won't affect it. Composer loads defaults to db prior to creating any component (on server not client)

In th-editor I don't think we need default for inputAttrs because with two way binding UI will be bound to the actual values anyways (the same values that are copied to currentState)

I like your solution, but if I am not wrong about above point, lets not use defaults for inputAttrs (and eventually remove them from metadata json if not needed).