docs-util: support models implemented with DML in typedoc custom plugins (#7847)

- Support generating reference for models implemented with DML
- Support resolving and generating mermaid diagram for relations

The Currency Module was used an example so its reference is generated to showcase the work of this PR.

www/utils/packages/utils/src/dml-utils.ts

@@ -0,0 +1,24 @@
+import { DeclarationReflection, ReferenceType, ReflectionType } from "typedoc"
+
+export function isDmlEntity(reflection: DeclarationReflection) {
+  if (reflection.type?.type !== "reference") {
+    return false
+  }
+
+  return reflection.type.name === "DmlEntity"
+}
+
+export function getDmlProperties(
+  reflectionType: ReferenceType
+): DeclarationReflection[] {
+  if (
+    !reflectionType.typeArguments?.length ||
+    reflectionType.typeArguments[0].type !== "intersection"
+  ) {
+    return []
+  }
+
+  const schemaType = reflectionType.typeArguments[0].types[0] as ReflectionType
+
+  return schemaType.declaration.children || []
+}

www/utils/packages/utils/src/index.ts

@@ -1,3 +1,4 @@
+export * from "./dml-utils"
 export * from "./get-type-children"
 export * from "./get-project-child"
 export * from "./get-type-str"