fix(ssr): support dynamic components that resolve to element or vnode

fix #1508

packages/server-renderer/src/index.ts

@@ -4,6 +4,7 @@ export { renderToString } from './renderToString'
 export { renderToStream } from './renderToStream'
 
 // internal runtime helpers
+export { renderVNode as ssrRenderVNode } from './render'
 export { ssrRenderComponent } from './helpers/ssrRenderComponent'
 export { ssrRenderSlot } from './helpers/ssrRenderSlot'
 export { ssrRenderTeleport } from './helpers/ssrRenderTeleport'

packages/server-renderer/src/render.ts

@@ -142,7 +142,7 @@ function renderComponentSubTree(
   return getBuffer()
 }
 
-function renderVNode(
+export function renderVNode(
   push: PushFn,
   vnode: VNode,
   parentComponent: ComponentInternalInstance