Make changes in default themes to avoid incompatibilities with old storefront version

[tatarincev]

Add {% Layout %} tag to all templates which are don't use default layout
Checkout, Account

Change Page.liquid template to always render static content
{% layout page.layout %} {{ page.content | render }}

Add to templates\customers\reset_password.liquid new lines

	  <input type="hidden" value="{{ reset_password.token }}" name="customer[token]" id="token">
	  <input type="hidden" value="{{ reset_password.email }}" name="customer[email]" id="email">
``` for correct password reset

(optional) Now instead CustomerInfo we are using User type which encapsulated  Contact as property need to change all js and templates according to this fact. Also, these changes affected the Cart and QuoteRequest model. 
List of files for change:  `Checkout.liquid`, `main.js`, `account.js` and other 

[Woland2k]

Why is this needed? Need to discuss further. We need to make old themes completely compatible without any changes.