Multisig fix

[onvej-sl]

• d99fea3 and cae49da disallow per-node paths which fixes https://github.com/satoshilabs/trezor-firmware/issues/191.
• d19cbfa introduces sorting of pubkeys in multisig which fixes https://github.com/satoshilabs/trezor-firmware/issues/193.
• 267c1c7 removes a path that is not used anymore (see https://satoshilabs.slack.com/archives/C01L1HT4B46/p1730908353546419). This was the only allowed path that doesn't end with /change/address_index. This caused some paths weren't properly recognized as change outputs. However, the main reason for removing this path is primarily to prevent further problems in the future.
• d9b7a57 forbid multisig to singlesig change outputs. This allows users to have greater control over where their funds are sent because since Send flow style update #2925, we also display the path for internal outputs. Nevertheless, this doesn't always work as expected, see Path doesn't fit line when confirming internal output on T3T1 #4319).

None of these changes were backported to legacy.

[github-actions]

core UI changes	device test	click test	persistence test
T2T1 Model T	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
T3B1 Safe 3	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
T3T1 Safe 5	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
All	main(screens)

[github-actions]

legacy UI changes	device test(screens) main(screens)