panels 8.x-3.0-beta6

This is a major release of panels that includes many panels IPE enhancements, some security features, wizards API, and better integration with workflow/workbench moderation.

Note: While this beta releases are not covered by the Drupal Security team, this release fixes the following access bypass issue:

Changes since 8.x-3.0-beta5:

• #2842779 by ccjjmartin, mishac: Update composer json for packages.drupal.org
• #2767087 by hideaway, samuel.mortenson: Re-index IPE blocks after invoking the alter hook.
• Various Code cleanup.
• #2785287 by samuel.mortenson: Panels IPE's nested form removal method is not robust
• #2767087 by DamienMcKenna, samuel.mortenson, floretan: Provide hook to alter available blocks for IPE
• #2850782 by vijaycs85: Multilingual support for Panels IPE
• #2832876 by abu-zakham: Need RTL completely support for right to left language like Arabic, Farsi, etc
• #2713257 by samuel.mortenson: Create Javascript test coverage for Panels IPE integrations with Panelizer and Page Manager
• #2709521 by samuel.mortenson: Cannot add site branding to panels variant
• #2687483 by phjou, doostinharrell, dobrzyns: Cannot switch variant layout
• #2828513 by albertski, TravisCarden, phenaproxima: User error: "max-age" is an invalid render array key in Drupal\Core\Render\Element::children()
• Added Panelizer as a test dependency.