Discussion: Cache::has seems never a good idea, deprecate it?

[mhsdesign]

see #3188
see neos/neos-development-collection#4595

@kitsunet and me discussed that its possibly always better to use get:

Is why I almost never use "has" in caches, it is never atomic, you cannot know what happens between has and get. I prefer

$cacheEntry = $cache->get(...);
if ($cacheEntry === false)  {
  die(); // early return, exception, whatever
}