Release SDK 2.8.0-preview.0

[vmarta]

What's new in 2.8.0: see #1507

• Update changelog files

Types of Changes

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Documentation update
• Breaking change (could cause existing functionality to not work as expected)
• Other changes (non-breaking changes that does not fit any of the above)

Breaking changes include:

• Removing a public function or component or prop
• Adding a required argument to a function
• Changing the data type of a function parameter or return value
• Adding a new peer dependency to package.json

Changes

• (change1)

How to Test-Drive This PR

• (step1)

Checklists

General

• Changes are covered by test cases
• CHANGELOG.md updated with a short description of changes (not required for documentation updates)

Accessibility Compliance

You must check off all items in one of the follow two lists:

• There are no changes to UI

or...

• Changes were tested with a Screen Reader (iOS VoiceOver or Android Talkback) and had no issues
• Changes comply with WCAG 2.0 guidelines levels A and AA
• Changes to common UI patterns and interactions comply with WAI-ARIA best practices

Localization

• Changes include a UI text update in the Retail React App (which requires translation)

[adamraya]

Do we want to release a new version of commerce-sdk-react-preview?

Knowing that the final version is living on NPM @salesforce/commerce-sdk-react

[vmarta]

@adamraya this will not be published because the package is marked as private: true.

[vcua-mobify]

The only change mentioned in the change logs is the moving of the CSP headers into runtime.

In #1507 there are entries for adding Storefront preview support. Should those be added here as well?

Edit: I see where those entries are now; they are already included.