Fix minor issues
Refactored the way the data is stored
Refactored model data extraction, added extra actions to the datagrid
Fixed data grid drop down not showing when opened
Working towards action
Refactored entity, entity instance and form

Fields are now responsible for mutating attributes before they are set on model,
also they are responsible for copying and checking whether the attribute is changed.

It's now possible to provide more presentational links (like `Printed version`) in the
schema (`exportPresentationActions`); those links're moved to the top menu of the form.

Refactored inline forms to make them less memory leaky.
Added possibility to save model with specified action
Updated assets
Added states for actions and fixed some issues
Fixed select input
Fixed select AGAIN
Fixed data grid actions issue