lncli: show fee_per_vbyte and local_close_tx in closechannel and closeallchannels output

[Suvrat1629]

Change Description

This PR updates the lncli closechannel and closeallchannels commands to include fee_per_vbyte and local_close_tx in their JSON output when available.

• Refactors executeChannelClose to send all close details (txid, fee, local flag) via a struct.
• Ensures both single and batch close flows print these fields in their output.

Fixes #9831

Steps to Test

1. Open a channel and close it using lncli closechannel with a custom fee.
2. Confirm the JSON output includes closing_txid, fee_per_vbyte, and local_close_tx.
3. Run lncli closeallchannels and confirm the output for each channel includes the new fields.

Pull Request Checklist

Testing

• [ ] Your PR passes all CI checks.
• [ ] Tests covering the positive and negative (error paths) are included.
• [ ] Bug fixes contain tests triggering the bug to prevent regressions.

Code Style and Documentation

• [x] The change is not insubstantial. Typo fixes are not accepted to fight bot spam.
• [x] The change obeys the Code Documentation and Commenting guidelines, and lines wrap at 80.
• [x] Commits follow the Ideal Git Commit Structure.
• [x] Any new logging statements use an appropriate subsystem and logging level.
• [x] Any new lncli commands have appropriate tags in the comments for the rpc in the proto file.
• [ ] There is a change description in the release notes, or [skip ci] in the commit message for small changes.

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[gemini-code-assist[bot]]

Summary of Changes

Hello @Suvrat1629, I'm Gemini Code Assist[^1]! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly improves the user experience for lncli channel closing commands by enriching their JSON output. Users can now immediately access critical information such as the transaction fee per vbyte and whether the closure was initiated locally or remotely, directly from the closechannel and closeallchannels commands. This enhancement provides more comprehensive details for better monitoring and automation of channel management.

Highlights

• Enhanced lncli Output: The lncli closechannel and closeallchannels commands now include fee_per_vbyte and local_close_tx in their JSON output, providing more detailed information about channel closures.
• Refactored Channel Closing Logic: The executeChannelClose function has been refactored to pass all channel closing details (transaction ID, fee, and local/remote flag) via a dedicated CloseInfo struct, improving data encapsulation.
• Consistent Information Across Commands: Both single channel and batch channel closing operations now consistently display these new fields in their output, ensuring a uniform user experience.

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[lightninglabs-deploy]

@nishantbansal2003: review reminder @suvrat1629, remember to re-request review from reviewers when ready