This option allows to compile the testnet app in a mode that allows
autoapproving any request, in order to measure the performance of
various operations either in speculos, or on a real device.

These tests are no longer worth the maintenance burden, as they test specific conditions and
only apply to an old version of the app protocol.
The corresponding tests for the newer version of the protocol are kept in the codebase.

It is useful to test that large amounts are shown correctly; instead of generating the psbt
synthetically, we hardcode a fixed psbt so we can hardcode the screenshots.