[Maps] Extract/inject references from server side embeddable

[crob611]

Canvas handles reference extraction and injection server side.

It doesn't appear that maps implements either inject or extract for the server side embeddable, so a workpad with a by value map embeddable that is exported is missing references from the map.

[elasticmachine]

Pinging @elastic/kibana-gis (Team:Geo)

[nreese]

Background

Canvas added support for by-value embeddable in 8.0. Canvas uses server embeddable to extract references from embeddable. Since maps does not register extract in server-side embeddable, by-value maps embedded in canvas will not expose index pattern references to canvas. This will only effect newly created canvas in 8.0 and onwards that use by-value maps.

Original extract logic added to client embeddables in #91567 (7.12).

Lens inject logic to client embeddable and extract/inject logic added to server embeddable with #96703 (7.15).

Looks like maps team missed the requirement for exposing extract/inject logic in the server maps embeddable.

[nreese]

Closed by #125599