fix(runtime-core): should not track dynamic children when the user calls a compiled slot inside template expression

[HcySunYang]

Fix: #3548

Edit:

Also fix #3569, at first I tried to fix issue #3569 in another independent PR(#3573), and then I realized the strong coupling between issue #3548 and issue #3569, so I merged them into this one PR.

Issue #3569 is another problem caused by the mixed-use of optimization mode and manual render function, technically, the user can get any VNode in the manually written render function, e.g.

setup(props, { slots }) {
  const index = ref(100)
  return () => {
    // get any vnode
    return slots.foo()[3].children[index.value]
  }
}

Suppose the initial value of index is 100, and then it becomes 999, then the old and new subTree may be:

// old
{ type: 'div', dynamicChildren: [vnode1, vnode2] }
// new
{ type: 'div', dynamicChildren: [vnode99], patchFlags: xxx }

Obviously, they are not comparable, and they may come from different levels.

The idea is, for slots, if the user manually obtains the contents of the slot by calling the slots function, we should be forced to bail out the optimization mode