Fix IBC NFT unshielding

[yito88]

Describe your changes

closes #4025

• IBC VP should check the unshielding transfer by enabling is_shielding
• The packet data in IbcMsgNftTransfer is incomplete. We need to set the NFT data before MASP VP checking

Checklist before merging

• If this PR has some consensus breaking changes, I added the corresponding breaking:: labels
  • This will require 2 reviewers to approve the changes
• If this PR requires changes to the docs or specs, a corresponding PR is opened in the namada-docs repo
  • Relevant PR if applies:
• If this PR affects services such as namada-indexer or namada-masp-indexer, a corresponding PR is opened in that repo
  • Relevant PR if applies:

[tzemanovic]

labelled with "breaking:protocol" due to a change in the native VP

[codecov]

Codecov Report

Attention: Patch coverage is 12.50000% with 42 lines in your changes missing coverage. Please review.

Project coverage is 74.05%. Comparing base (e768857) to head (68915eb).
Report is 46 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/ibc/src/lib.rs	12.50%	42 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4027      +/-   ##
==========================================
- Coverage   74.09%   74.05%   -0.04%     
==========================================
  Files         341      341              
  Lines      107204   107249      +45     
==========================================
- Hits        79428    79426       -2     
- Misses      27776    27823      +47     

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