Get rid of `felt_into_bool` and `bool_into_felt`

[piwonskp]

Serialization code should be refactored to use generic functions within https://github.com/NethermindEth/warp/blob/cairo-1.0/warplib/src/warp_memory/accessors.cairo#L95 instead of using conversion functions and then writing to the memory.

After refactoring felt_into_bool and bool_into_felt (https://github.com/NethermindEth/warp/blob/cairo-1.0/warplib/src/conversions/integer_conversions.cairo#LL20C40-L20C40) should be removed