Allow to use patterns in the Mount#pathSupportingFragments

The pathSupportingFragments field allows to configure subtrees under which the nodes with names containing oak:mount-MOUNT_NAME fragment are redirected to a non-default mount.

It's used when running Oak on composite node store - in this case, the indexing data have to be split between different node stores and setting the pathSupportingFragments to /oak:index allows to do this.

However, in terms of the composite node store performance, this option is pretty expensive. Setting it on a low-level path like /oak:index means that all the node states below this path has to be wrapped with the CompositeNodeState objects and we can't fallback to the native Segment/DocumentNodeStates. For example, the node:

/oak:index/lucene

has to be composite, because it's children may belong to the default (:index) or non-default store (:oak:mount-libs-index. However the children themselves doesn't need to be wrapped anymore.

In order to improve this, we should support patterns in the pathSupportingFragments entries. The pattern is a normal path, but supporting two special characters:

• * - matches a sequence of characters different than /,
• $ - matches the end of the path.

Then, we can define the pathSupportingFragments with the following pattern:

/oak:index/*$

For example, it'll match following paths:

/oak:index/uuid
/oak:index/lucene

but not these:

/oak:index
/oak:index/uuid/:index