[core][studio] Inject element's source descriptor during merging

[sumerjabri]

Merged artifacts must include an element attribute indicating the source descriptor if different than the descriptor being loaded (think inheritance).
The attribute name is: src

• Update Core
• Update Engine
• Update Studio
• Update ICE to become aware of src element and leverage it to better author

[jdrossl]

@rart the new API for studio is ready

[rart]

@jdrossl

• Can't find this on swagger?
• Is it possible to send flatten=false through the studio API? Can we propagate the options to the engine API?

[jdrossl]

@rart the docs have been updated:

• New Studio API: https://app.swaggerhub.com/apis/craftercms/studio_3_2/3.2.0.1#/content/getDescriptor
• Updated Engine APIs: https://docs.craftercms.org/en/3.2/developers/projects/engine/api/index.html#site-content-store

for all of them the parameter is optional and false by default

[rart]

@sumerjabri we didn't include the flatten option on the studio side. This disables the possibility of doing progressive loading of the content items.

PageBuilder is covered as this, by default, returns the whole content tree flattened but Form engine would benefit from the reduced/progressive on-demand payload. Also, since this is published as part of the npm studio-ui package, having the option provides additional versatility for the community to create (e.g. studio plugins) in whatever way it fits best for their use case.

I don't see value in hiding the option.

Can we include it?

[sumerjabri]

@rart yes
@jdrossl please make flattening optional. @rart is saying that it's permanently on right now for Studio's version of this API.

[rart]

As an additional item, please add an attribute containing the content type id of the source file: crafter-source-content-type-id). For example:

<header_o 
  crafter-source="/site/website/crafter-level-descriptor.level.xml"
  crafter-source-content-type-id="/component/level-descriptor"
>
    <item>
      ...

[sumerjabri]

@jdrossl please work on this after CLI and then assign back to @rart

@rart this remains a low priority ticket from your perspective

[jdrossl]

@rart both updates are merged now

[rart]

PageBuilder's ICE now recognizes inherited zones and allows editing the level descriptor.