Remove legacy BIP70 merchant name from tx details window #970

BIP70 is now dead for roughly half a decade. There is no need to print the merchant name in the tx details window, so remove that feature.

The parser has no tests, nor fuzzing, so removing it will likely also fix some parsing issues with corrupt data.

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Conflicts

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• #bitcoin/bitcoin/36033 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/36033.svg">} ([wip,nomerge,rfc] build: Require C++23 compiler by maflcko)

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Obviously no rush to remove this ~dead code, but it would be nice to have it in the next release, to make it easier to review the code for real bugs.

lightweight code review ACK fa917ddcb1c7a2612dd8e57c3ef75e443cc8a962