refactor: introduce product context

[dhhyi]

PR Type

[x] Application / infrastructure changes

What Is the Current Behavior?

Component composition also includes bubbling of data and events that could be handled by contexts for products.

What Is the New Behavior?

Major refactoring:

• counter component as default quantity component (now with editable input and not just buttons)
• support step order quantity (currently only correctly working for detail pages, waiting for IS-31849)
• refactored the way properties of products are displayed on detail-page, product-tile, product-row - Closes Variation Master - Different buttons are displayed on tile view, list view and product detail page #492
  • removed tacton specifics from product-detail, product-tile, product-row
  • display decisions moved into context-facade, replaces fix: show/hide logic for addToCard, quantity, addToQuoteRequest #42
• product-quantity handling moved to context-facade
  • error handling implemented there
  • removed forms wherever possible
  • removed bubbling for order-templates, product bundles, product retail sets
  • form work-arounds removed from line-item lists
• refactored product variation selection

-> less logic in templates, components

Still open for later:

• refactor quickorder page
• promotions, inventory, product-image components could also use context

Does this PR Introduce a Breaking Change?

[x] Yes
[ ] No

[M-Behr]

This is a very cool new quantity component. I like it.

Behavior issues:

• If you have a product in the cart and you enter 0 in quantity field or use the arrow, the product is removed. The new component displays an error message in this case. It is possible to enter 0 or use the "-" button to remove the product from the cart?
• The quantity field is very large in phone or tablet view on some pages. It think width: 50% is fine for the smaller breakpoints, where the component has the whole line or we can define a max. width for the component (maybe 165px - component size in product detail page)?
  

Some styling issues:

• The left border of the focus effect is missing in the cart => This only appears in the cart, maybe it is not a component issue?
  
• Space is missing between quantity component and add to cart (wish list page).
  
• A blank character is missing after product attribute label in the product list component for variation products.
• The variation product attributes have 8px margin between them. Please remove it, so that the attributes are grouped together.
  
  Note: I saw that the font color of the product variation attributes was changed from 444 to 999. This is fine for @iwiederhold and me.