check allowChildContentType filter in content API

[rymsha]

8720 provides a front-end filtering for allowChildContentType

Validate new content create and move actions based on allowChildContentType

Key differences:

• allowNewContent should not be checked. (Create Content API already prevents "abstract" content)
• Frontend does not show media content types, validation should allow them in root and normal content (by default)
• (?) do not check for for applications in nearest site. Nearest site is a recursive function, potentially scanning a lot of content. Second reason is: move/create may fail miserably due to application with content-type temporary stopped/uninstalled.

[rymsha]

Move Content API checks

• allowChildContent on destination parent is true

So it is possible to move template-folder and page-template anywhere. Is it by design or a bug?

Create Content API checks

• template-folder is created in site parent
• page-template is created in template-folder parent
• content's type is not abstract

So it is possible to create content in parent with allowChildContent = false. It seems like a bug. (correction: the check is in populateParentPath) Even more: if parent allowChildContent = false and parent is page-template, nearest site is looked-up (it is usually fast in this case, just two steps, but sometimes fails), to substitute parentPath with nearest site's path. https://github.com/enonic/xp/issues/4820

[rymsha]

page-template should allowChildContent = true but allowChildContentType = media:* and portal:fragment such content should go under page-template itself, not under site

[rymsha]

if content-type is currently unavailable assume it allows any child content type

[rymsha]

So it is possible to move template-folder and page-template anywhere. Is it by design or a bug?

Bug or not, logic gets changed: now create and move share the same parent-child relationships verification.

• template-folder can only be created/moved under site
• page-template can only be created/moved under template-folder
• allow-child-content is respected for both create and move operations
• allow-child-content-type respected for both create and move operations