Add default value to Configuration.scope parameter to make it optional

[zzooeeyy]

Relates to

• Add default value to Context::scope parameter to make it optional shopify-api-ruby#1343

What this PR does

Fixes:

• Why do we have to declare the scopes and api version on the ShopifyApp.configure if we already declare them on the .toml config file? #1912

Background

The scope parameter was required as a part of the legacy OAuth flow (Authorization code grant).

• It used to be a required parameter during the ShopifyAPI::Context setup process, but has been changed to be optional from this PR
• ShopifyApp.configuration does not have explicit expectation for config.scope to be configured, but it will encounter an error during OAuth from ShopStrategy

Solution

Making ShopifyApp.configuration.scope to have a default value [] so it can be omitted during setup.

How has this been tested?

• Linked a local version of ShopifyApp with my changes to my app
• Removed config.scope setup in the ShopifyApp.configure method
• Start installation process and observe no errors:
  • With Shopify managed install configured: config.scope values are ignored during installation
  • With Shopify managed install disabled: config.scope values are used during installation

Checklist

Before submitting the PR, please consider if any of the following are needed:

• Update CHANGELOG.md if the changes would impact users
• Update README.md, if appropriate.
• Update any relevant pages in /docs, if necessary
• For security fixes, the Disclosure Policy must be followed.