Tracking issues of integration virtiofs

[zjregee]

Since we have integrated virtiofs, this issue is used to track the remaining issues.

Roadmap

• Add init: feat(ovfs): add filesystem to handle message #4720.
• Export VirtioFs to support the use of virtiofs: feat(ovfs): export VirtioFs struct #4983.
• Add lookup and tests for reading and writing data to shared memory: feat(ovfs): support getattr and setattr #4987.
• Support file creation and deletion: feat(ovfs): add file creation and deletion #5009.
• Support file data reading and writing: feat(ovfs): support read and write #5016.
• Add necessary end-to-end tests in CI.
• Add README and related docs.