[FEATURE] Support fuse for Fileset

### Describe the feature

Implement fuse for gvfs to support mounting fileset to local directories. The instance defaults to mounting `fileset://fileset/fileset_catalog/schema/fileset_name` to `/fileset/fileset_catalog/schema/fileset_name`. So we can access it via posix protocol. In addition, we can support mounting to user-defined directories, so that users do not need to modify any code.

### Motivation

In AI scenarios, users often use the posix protocol to access data. The data is stored in media such as JuiceFS, NAS, or CPFS, and then mounted to a local directory.
Directly using these storage has the following disadvantages:
1. Authentication issues: Each product has its authentication system, and users have a high access cost
2. Authorization issues: When users share data, they need to share the permissions of the entire volume, and there is no way to perform fine-grained permission control
3. Audit issues: Some NAS products lack audit logs, making it impossible to perform effective audits and data deletion

### Describe the solution

1. Use the underlying fuse directly.
This means that fileset needs to manage a local directory. I think this is not a good solution, users will bypass gvfs without any benefits.

2. Using fsspec fuse to implement gvfs fuse
fsspec provides the feature of fuse, which supports forwarding fuse operations to fsspec fs operations: https://filesystem-spec.readthedocs.io/en/latest/features.html#mount-anything-with-fuse
We could do some optimization based on fsspec fuse to support gvfs fuse.

3. Implement gvfs fuse using JNI to call GravitinoVirtualFileSystem

At present, Solution 2 and Solution 3 are similar. Solution 2 is implemented by calling Python gvfs, and Solution 3 is implemented by calling Java gvfs.

### Additional context

_No response_

Read the linked fsspec “mount anything with FUSE” feature and compare it with the proposed JNI approach for Java gvfs. The issue describes support for mounting fileset:// paths at their default local directories and at user-defined directories; completion should cover both behaviors and POSIX access.

Written by the indexing model from the issue text.