Move all webform element properties to static definitions and allow them to be altered and cached

Problem/Motivation

It is very difficult to alter and enhance webform element properties.

Proposed resolution

Move all webform element properties to static definitions and allow them to be altered and cached while maintaining some backward compatibility

• Makes it very easy for element properties to be removed from the UI
• Makes it easier to add custom element properties to the UI
• Makes it possible to change an element's default property

Notes

• Deprecate code using #3024296: Add option to log deprecation errors
• Require all properties to define a 'default' value
• Use Webform plugins: Elements report to review changes. (/admin/reports/webform-plugins/elements)

Remaining tasks

• \Drupal\webform\Plugin\WebformElementManager add new methods
• WebformElement - Convert class property methods to static methods
• Add dedicated 'Property definition' section to WeformElement.
• Able to use static method on WebformElement without the WebformElementManager

User interface changes

None

API changes

• WebformElementBase::getDefaultProperties => WebformElementBase::propertyDefinitions
• WebformElementBase::getTranslatedProperties => WebformElementBase::translatedProperties
• Deprecated WebformElementBase::getDefaultMultipleProperties => ::properyMultipleDefinitions()
• Deprecated WebformElementBase::getDefaultBaseProperties => ::properyBaseDefinitions()

Hooks

• hook_webform_element_info_alter

Data model changes

The same data structure, using a different method.

Release notes snippet

• Property help methods will be deprecated and moved to static methods.