Feature: Version 2.x reintroduce disabling nodes (_hidden=true)

[mhsdesign]

With pr the functionality to set internal node properties via _foo property syntax, which was introduced with was reverted. This was done in preparation for the Neos 9 ESCR to be forwards compatible.

The most requested internal property properties._hidden is now available via tags.disabled.
- The idea of tags is back-ported from Neos 9 where the Node will be tagged as disabled or possibly a custom value. See SubtreeTags. Naturally Neos 8.3 can only support the disabled/hidden case and thus other values will throw an exception.
- The name shift from hidden to disabled was done to adjust to the naming of the new ESCR. See explanation.

This is WIP as the naming of using hidden vs disabled is not 100% clear yet. Thats why this was omitted from the Version2 release but once we find a solution we will release a new version with support for this.

Discussion: neos/neos-development-collection#4312

'Flowpack.NodeTemplates:Content.Disabled':
   superTypes:
     'Neos.Neos:Content': true
   options:
     template:
       tags:
         disabled: true
       properties:
         someProperty: "value"

Regarding the naming of the new option tags. The term is already partly overloaded and could be mistaken but the reasoning was to align it with the new Neos 9 Api. While more explicit we decided against subtreetags as this term is only used in the cr-write-side and thus more low-level and less know by the integrator. The name tags as in Node::$tags (see NodeTags) will be part of the Neos 9 API and hopefully a known and understood concept by the user.

https://github.com/neos/neos-development-collection/blob/f640f70321f6a96837dbea86ce1d11c72368c924/Neos.ContentRepository.Core/Classes/Projection/ContentGraph/Node.php#L128

see also voting: #55 (comment)

[mhsdesign]

With the introduction of subtreetags in Neos9 we could also introduce a subtreetags option but as disabled is a core concept we should probably expose it on a higher level:

'Flowpack.NodeTemplates:Content.Hidden':
   superTypes:
     'Neos.Neos:Content': true
   options:
     template:
       disabled: true
       # alternative
       subtreetags:
         disabled: true
       properties:
         someProperty: "value"

[mhsdesign]

I started a voting in slack regarding the syntax:

option1 1️⃣, first level disabled (no support for custom subtreetags)

'Vendor.Site:Content':
   options:
     template:
       disabled: true
       properties:
         foo: 'bar'

option2 2️⃣, nested tags , to also allow custom SubtreeTags in Neos9

'Vendor.Site:Content':
   options:
     template:
       tags:
         disabled: true
         # blog: true
       properties:
         foo: 'bar'

option3 3️⃣ , allow both tags and disabled: true first level (basically option1 and option2 combined)

---

we voted with 6 votes for option2 2️⃣