* Makes ParserCache take the root of the key
as a constructor argument
* Introduces a ParserCacheFactory
Next steps:
- convert FlaggedRevs to using this.
- cleanup
This assumes that we wouldn't want to differentiate
the parser cache settings per use-case, as it is now
for default vs flaggedrevs caches. There are only two settings:
$wgParserCacheType - name of the BagOStuff to use
$wgParserCacheExpireTime - the expiration time.
I think if we wanted to have different settings for different
caches, we could add that as a next step.
Bug: T263583
Change-Id: I188772da541a95c95a5ecece7c7dd748395506c2
