Merging address autocompletion feature to develop branch.

Description

Merging address autocompletion feature to develop branch. The changes included are from previously approved PRs. https://github.com/SalesforceCommerceCloud/pwa-kit/pull/2614 https://github.com/SalesforceCommerceCloud/pwa-kit/pull/2767 https://github.com/SalesforceCommerceCloud/pwa-kit/pull/2886 https://github.com/SalesforceCommerceCloud/pwa-kit/pull/2981 https://github.com/SalesforceCommerceCloud/pwa-kit/pull/3209

Types of Changes

[ ] Bug fix (non-breaking change that fixes an issue)
[x] 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

New environment variable (GOOGLE_CLOUD_API_KEY) that allows customers to enable the address autocompletion feature in checkout (and any address fields)
Address suggestions from Google Maps Platform are displayed to the user upon 3 or more characters in the input field
Address autocompletion for address fields upon choosing an address suggestion from the dropdown

How to Test-Drive This PR

Add an item to the cart and go to checkout. Fill out your contact information to go to shipping address section.
Country is auto-selected (United States), can change if you want.
Start typing 3 or more characters in the Address field.
Address Suggestions dropdown should be displayed to the buyer, with an option to temporarily close it (X icon).
Upon choosing an address suggestion, the address fields should be automatically populated.
Try the same with billing address (specify that it's different from shipping address).
Checkout can be completed as expected.

Checklists

General

[x] Changes are covered by test cases
[x] 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