Issue/5612 - Alignfull class not working on columns

[jvisick]

Description

The column block isn't outputting alignment classes to the front-end. I think we can fix that and update the block to the supports align extension in one fell swoop.

Fix for #5612.
Related to #5099. (cc @gziolo )

How Has This Been Tested?

Tested locally by adding a column block to a new page, setting it to alignwide, saving and viewing the output markup on the front-end.

Types of changes

Changes to the columns block index.js file by removing any alignment related code and adding:

supports: { align: [ 'wide', 'full' ], },

Bug fix (non-breaking change which fixes an issue)

However, this will cause existing saved column blocks with to throw a validation error since it will now be expecting the class to be in the saved markup. I don't know a way around that?

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code has proper inline documentation.

[gziolo]

The same changes are included in #5099. We haven’t landed them because we discovered a blocker: #5099 (comment). We want to make sure we find the viable solution which allows to handle attributes properly for all type of blocks. We are leaning towards moving attributes to the server to have only one place to apply all required hooks to make align work. Once it is resolved we can get back to this change.

[skorasaurus]

Will this be addressed with this PR since #5099 has been closed?

[gziolo]

Columns block was deprecated, so I don't think is relevant anymore. See #8036.

[gziolo]

Wait, Text Columns was deprecated :) Anyways, I see that it was implemented for Columns block by @jorgefilipecosta:
https://github.com/WordPress/gutenberg/blob/master/packages/block-library/src/columns/index.js#L65-L67

Related PR: #6364.