[Prototype] Force shutdown routine to be run

[georgwiese]

Hacky version of (hopefully) sound continuations (#814). These added constraints should force the prover to set the jump_to_shutdown_routine flag correctly, e.g.:

• It should not be set while still in the bootloader
• After the bootloader, it should be set exactly once
• The shutdown routine should have enough time to actually finish

This is only a hacky implementation, because we could not have added these constraints already. For example:

• The PC update rule is replaced
• Accesses the instr_jump_to_bootloader_input flag to find out if the bootloader has finished
• Accesses the pc_update intermediate polynomial to make sure that the final PC is exposed correctly in the bootloader inputs.

To test:
PILCOM=$(pwd)/pilcom/ cargo test --all --all-features --profile pr-tests -- --ignored --exact test_many_chunks_memory

[leonardoalt]

@georgwiese just curious: can #1221 be used for the pc stuff here?