Local cache repository for Remote XSD

[HandOfGod94]

Implement a cache repository, preferably using h2, to store XSD fetched from Remote
Future release should also handle DTD files.
The lookup for xsd will first take place in this cache and then will try to fetch it from the remote.
It should handle multiple versions of xsd too.

[HandOfGod94]

Since the URI be it remote or local, can be easily resolved by xerces, the XSModel loaded by xerces can be somehow then cached using guava-cache rather than having separate repository for it.
For alpha release the guava-cache should be good enough, for future release, it will be helpful if we could somehow cache the repository locally.