feat(framework): implement invalidateParent

[fifoosid]

No description provided.

[vladitasev]

Apart from the comments in the code, there is one more thing I can think of: we should revert the variable back go false when a child leaves the parent (otherwise if the user adds the child to another parent, it will continue invalidating the new parent, although it might not have set such metadata).

Probably a good place to do this would be after this._detachChildPropertyUpdated(child); in the same if statement:

children.forEach(child => {
			if (child && child.isUI5Element) {
				this._detachChildPropertyUpdated(child);
			}

			if (isSlot(child)) {
				this._detachSlotChange(child);
			}
		});