[Additional Screenshot] PSBT Review: Before verifying multisig change addr

[kdmukai]

Description

Adds a screenshot to the screenshot generator for the PSBT review screen that displays a change addr that has not yet been verified via the multisig descriptor:

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Note: We already have a screenshot for the "After" state where the change address has already been verified.

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This pull request is categorized as a:

• [x] Other

Checklist

• [x] I’ve run pytest and made sure all unit tests pass before sumbitting the PR

If you modified or added functionality/workflow, did you add new unit tests?

• [x] Yes

I have tested this PR on the following platforms/os:

• [x] Raspberry Pi OS Manual Build
• [ ] SeedSigner OS on a Pi0/Pi0W board

[newtonick]

Tested and looks good.

The existing screenshot file "PSBTChangeDetailsView.png" is renamed to "PSBTChangeDetailsView_multisig_verified.png" and the new screenshot file is named "PSBTChangeDetailsView_multisig_unverified.png".