fix: Validate prevouts in get_psbt_input

[evanlinjin]

Fixes #50
Fixes #51
Replaces bitcoindevkit/bdk#1911
Replaces bitcoindevkit/bdk#1913

Description

We should check the bounds of the prev txs.

Changelog notice

Fixed:
    - Wallet::get_psbt_input method now checks bounds when fetching prevout
    - Wallet::build_fee_bump method now checks bounds when fetching prevout

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

Bugfixes:

* [ ] I've added tests to reproduce the issue which are now passing

• I'm linking the issue being fixed by this PR

[coveralls]

Pull Request Test Coverage Report for Build 15063236968

Details

• 15 of 19 (78.95%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.009%) to 86.061%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
wallet/src/wallet/error.rs	0	2	0.0%
wallet/src/wallet/mod.rs	15	17	88.24%

Totals
Change from base Build 14921254296:	-0.009%
Covered Lines:	7273
Relevant Lines:	8451

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💛 - Coveralls