✨ Implement asynchronous responses for GoogleBusiness

[m-ripper]

Proposed changes

The GoogleBusiness-platform is now capable of sending multiple responses asynchronously.
Now, it is possible to answer with multiple messages to a single request.

• Implemented the method showText to immediately send a text message.
• ⚠️ Changed the behavior of showCarousel and showStandaloneCard to immediately send their respective rich-card.

Additionally, a method setFallback was implemented which allows setting a fallback-value for the response. For more information about the fallback-value, take a look here.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed