Allow pre-defined delivery options

[NickolayGett]

Is your feature request related to a problem? Please describe.
If the customer decides to adjust his delivery options after the data was sent and he left the page, going back will require him to fill in the information from nothing. I could not find a option to pre-fill the delivery options on render or update events.

Describe the solution you'd like
Add "delivery_options" to window.MyParcelConfig with the structure of the contents of #mypa-input that will allow customers to edit what they picked previously.

If I missed some configuration that can make this happen, please let me know. Thank you.