Use metaData and formData

[polmiro]

Sometimes we use the formData to transfer information thorough the form structure that is not actually relevant. Some examples would be:

• Typeahed uses "field_name_typehead" when the id transfered is not the same as the title displayed.
• DynamicForm uses "field_name_form_def".

I think it would be ideal to have a metaData data object that is transferred to the input elements, this can be updated by DataSourcedMixin, and then other form elements can react to those changes.

[polmiro]

This is related to making the form components immutable. All they would do is propagate a pair(metadataKey, value) to the parent component

[polmiro]

Metadata should also be used in DataSourcedMixin.

Instead of storing "options" and other sourced data as state, we should propagate it to the parent component (as we do with formData).

I'm still not certain where the data resolution should be done. Whether pass "formData" + "dataKey" down the line or just pass the "data" itself. (same thing regarding metadata).