Event listeners not removed for ReorderableRow and ReorderableColumn

[woppa684]

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Copied from #11357 (which was partly solved and then closed)

The main problem is in the implementation of both the unbind methods for ReorderableRow and ReorderableColumn. To illustrate this, a small excerpt from one of the bind functions:

primeng/src/app/components/table/table.ts

Lines 3315 to 3316 in 3fe4a80

	this.mouseDownListener = this.onMouseDown.bind(this);
	this.el.nativeElement.addEventListener('mousedown', this.mouseDownListener);

And the corresponding unbind:

primeng/src/app/components/table/table.ts

Lines 3333 to 3336 in 3fe4a80

	if (this.mouseDownListener) {
	document.removeEventListener('mousedown', this.mouseDownListener);
	this.mouseDownListener = null;
	}

As can be seen, the listeners are registered on the nativeElement but removed from the document (where the listener was never registered), leaving the event listeners on the nativeElement behind. One could argue that, as the element is removed also the listeners get cleaned up, but this does not work for every usecase. Also, it seems that the idea was to have unbind methods, so let's make sure that they're correct :)