webform 8.x-5.0-rc8

Change records:

• Added support for custom dismissible messages and a notification system
• Conditional logic (ie #states) is now applied to submission preview and view
• Add related resources below Webform help videos
• Webform Demo: Event Registration System module now shows how to use webform node's fields to override a webform's settings.

Changes since 8.x-5.0-rc7:

• #2957344 by jrockowitz: Composite data is being lost when navigating back from a form preview
• #2957272 by sorinb: Failed: Invalid character in Config object name [error] webform.settingProvide dedicated 'test' webform operation and access rule. s
• #2956752 by jrockowitz: Update external libraries
• #2957196 by bgilhome: 'Back to form' button source entity URL not translated
• #2957192 by jrockowitz: Add postal_code to test data
• #2956511: Add support for custom message storage and setup for webform help notifications.
• #2956511 by jrockowitz: Add support for custom message storage and setup for webform help notifications
• #2939414 by jrockowitz: Invisible elements should be hidden on preview page
• #2951368 by jrockowitz: Provide dedicated 'test' webform operation and access rule. Fix update hooks.
• #2955881 by jrockowitz: #multiple__label and #multiple__labels are being saved with every element
• #2955945 by jrockowitz: Add related links to videos
• #2955056 by jrockowitz: Webform field configurtion - limit submissions
• #2955754 by jrockowitz: Codemirror element is attempting to parse invalid YAML