commerce 8.x-2.0-beta5

Major changes since beta4:

• An API for off-site payment gateways (with a matching example in the payment_example module)
• Order activity logs (via the new commerce_log submodule)

Changes since 8.x-2.0-beta4:

• #2839060: Create an API for entity logs
• #2827747 by cornifex: Refactor commerce_cart_commerce_order_presave() into a transition event subscriber
• #2835820 by mitrpaka: Add a kernel test for the promotion entity (#587)
• #2838978 by bojanz: Allow offsite gateways to be used without checkout
• #2838953 by bojanz: The offsite redirect auto-submit fails on some themes
• #2838460 by mglaman: Allow adjustment field to be configurable on form (#584)
• Fix the PaymentGateway plugin sort.
• Make sure that checkout complete never has any buttons (offsite-commit regression).
• #2838472 by mglaman: Do not allow NeedsRedirectException to be cached (#585)
• Improve on-site payment gateway code documentation.
• Merge pull request #581 from mglaman/offiste-payments
• Sort the gateway plugins on the admin add form, fix tests.
• #2785591: Finalize the off-site API.
• #2785591: Make payment gateway plugins aware of the parent config entity ID.
• #2785591: Initial implementation of an off-site API.
• #2833140: Remove $priority from resolvers since the implementation is incomplete
• #2831839 by a.dmitriiev: PriceCalculatedFormatter doesn't always load the referenced currency
• #2835097 by Bcwald, bojanz: Commerce toolbar integration adds an empty link to the toolbar
• #2826693: Content translation breaks the promotion forms
• Clean up PromotionForm, fix the redirect url.
• #2833000 by skyredwang, bojanz: Price::greaterThan() must be an instance of Drupal\commerce_price\Price
• #2832595 by bojanz, steveoliver: Payments tab on orders no longer shows up
• #2835048: The order receipt email is not sent to anonymous customers
• #2836002 by marthinal: Add the order to the parameters to build the email
• #2835862 by bojanz: The payment gateway add form can be saved without credentials
• Fix build with latest coder (codestyle checks).
• #2835078 by Lendude: ProductAttributeValue doesn't have an access handler
• #2835667 by janchojnacki: Promotion usage methods return date value
• #2834627: Promotion percentage can't be provided in the locale-specific format
• #2832797 by bojanz, a.dmitriiev: Promotions cause PluginNotFoundException
• Fixed broken link to docs in readme (#579)