feat: Add SEQPACKET socket type support for vsock

[sumansaurabh]

Summary

Implements SEQPACKET socket type support for virtio vsock to enable datagram relay use cases while preserving packet boundaries.

Changes

• Added VIRTIO_VSOCK_F_SEQPACKET feature flag support
• Implemented SOCK_SEQPACKET socket type handling in vsock implementation
• Added socket type validation to ensure host UDS matches vsock socket type
• Updated connection logic to handle SEQPACKET connections appropriately

Why

This addresses the limitation where VMs relaying datagrams over vsock need to preserve packet boundaries, which SOCK_STREAM combines together. The SEQPACKET type maintains message boundaries while providing reliable, ordered delivery.

Testing

• Verified SOCK_SEQPACKET socket creation and connection establishment
• Confirmed socket type mismatch rejection between guest and host
• Validated packet boundary preservation in data transmission

Fixes #4822

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This PR was created from task: https://remote-code-1.onrender.com/tasks/hATFTs3x7VF1zV1Wokznz