[ECP-9072] Implement backend requirements of PayPal express

[candemiralp]

Summary

Required dependencies have been upgraded and new definitions have been included to support PayPal express. While implementing the new fields, some refactoring has been done to simplify the code and remove the duplications.

• Button block model classes implement PAYMENT_METHOD_VARIANT as Adyen payment method tx_variant.
• Express payment methods now use respective payment method's configuration path.
• Abstract template is used instead of individual templates.
• Observers to add payment methods now uses an abstract observer.
• Following constants have been deprecated.
  • APPLE_PAY_BUTTON_COLOR_CONFIG_PATH
  • SHOW_APPLE_PAY_ON_CONFIG_PATH
  • SHOW_GOOGLE_PAY_ON_CONFIG_PATH
• Following methods have been deprecated.
  • getShowApplePayOn()
  • getShowGooglePayOn()

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud