Bug fixes

Adding better error handling based on the response from Watson.

Fixing serialization of checkboxes and multiselect fields.

Removing unused code and fixing coding standards.

• Review asset exporting and entity preview PR
• Make the acquia_contenthub.client service public.
• Modules support new service webhook status.
• Last set of changes to clarify and simplify various elements of the code.
• Removing the webhook status checking code from the controller in favor of the new code in the library.
• Making sure all references to the messenger property use the method instead.
• Converting over to the new webhook object from the library.

* Issue #3064249 by gun_dose: When checked "multiple" and disable "implode", view always shows first item
* Refactoring of the code using drupol/drupal-conventions package.

Fix error 500 when service is not available.

New features, and bug fixes. History mechanism disabled for now, pending rewrite.

Minor update that mainly fixes a bug where RC3's update hooks were insufficient. Now, every view should be properly updated to use the new cache contexts without the need for people to manually edit and resave the view.