[Feature] allow PinotFSFactory register same scheme with different configurations

Currently there's no way to create/register multiple PinotFS instance for the same scheme.

This is useful when access secrets need to be separately configured for different part of the same file system scheme (for example: S3 with different bucket)

Start by reading the PinotFSFactory entry point named in the issue and trace how a scheme is registered and configured. The change is complete when multiple PinotFS instances can use the same scheme with separate configurations, including distinct access secrets such as for different S3 buckets.

Written by the indexing model from the issue text.