fix: validate taproot control block conversion

[reez]

Description

Reject invalid Taproot output key parity and mismatched leaf versions during PSBT input conversion (which prevents silent control block corruption).

Notes to the reviewers

Documentation

• bdk_wallet
• bitcoin
• uniffi
• Other:

Changelog

Checklists

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• I've signed all my commits
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• I ran cargo fmt and cargo clippy before committing
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• I've linked the relevant upstream docs or specs above

New Features:

• I've added tests for the new feature
• I've added docs for the new feature

Bugfixes:

• This pull request breaks the existing API
• I've added tests to reproduce the issue which are now passing
• I'm linking the issue being fixed by this PR