Bug fixes

Issue #3005475 by lussoluca: Remove Execute PHP feature
Issue #2914657 by lussoluca: Cannot use object of type Closure as array
Issue #3003353 by Stacie_A: Capitalize the Devel Generate module name.
Issue #2987782 by lussoluca: Add the Symfony var-dumper component as a dependency
Issue #2999892 by guillermo-simeon: function dd is already defined in symfony since Drupal 8.6
Issue #3001202 by stefan.korn: Devel tests are failing
Issue #2987140 by volkswagenchick: Fix README, useful links and formatting.

Enhancements in dynamic and customized markers (Issue #2794993)
Added the shadowSize option for the customized Marker.
Better UI Messages.

Bug fix for auto select, cleanup, and new class added for editable

Issue #3028710 by mferanda: Auto select is not working on cell edit
Issue #3029217 by mferanda: Some minor JS cleanup
Issue #3029307 by mferanda: Add css class to cell item if editable (on edit mode)

* Prevent a user from updating their currently active subscription
to the same billing plan, unless the subscription is on a grace
period (ie. will cancel at period end).

* prevent duplicate submission of the Subscription Update form. In the scenario where a user creates a new subscription via the update subscription form, and they click the "confirm" button multiple times rapidly, this fix prevents the creation of orphaned subscriptions in Braintree for which no local subscription entity corresponds.

Naming convention and settings update.

#2968459: Add tokens for links to the entity you're forwarding
#2968659: The 'link' variable in forward.twig.html should be absolute