none of the decoders and evaluators should allocate

[Krastanov]

evaluate_decoder might evaluate a couple of times during setup, but there should be no new allocations happening when we enter the sampling&decodeing loop. This would require removing allocations from:

• the various LDPCDecoder.jl decoders
• the various PyQDecoders.jl decoders
• probably using batched in-place decoder interfaces for all of them (see In-place and batch decode functions #217 )
• removing allocations from evaluate_decoder itself
• add tests that verify that future changes do not cause things to allocate again (potentially including tests inside of the LDPCDecoder and PyQDecoder libraries)