Use random suffixes for dropbutton items HTML ID to prevent collisions

This is a follow-up of #2939166: Clicking "edit" dropdown button navigates to incorrect content.

Original issue attempted to fix the collision problem with suffixing IDs with the current timestamp. However, problem still sometimes persists with that solution.

I have a page with two views, both with entity operations links. Sometimes it happens that I get same timestamp/ID on both views and then the links stop working. I am not sure why Html::getUniqueId() isn't picking this up and adding a suffix at the end. It is really hard to debug this as it sometimes appears and sometimes not.

I propose to use cryptographically secure random string as a suffix. This should prevent collisions for good I think.