Adjust tests in bound_checks.rs to fully verify WASM Opcodes

[g4titanx]

the native SafeNumeric tests implemented earlier in bound_checks.rs are simply not important for Zink’s context. we need to update it to use WASM FFI calls (asm::addmod_i8, ffi::u256_add, etc.)

[Timosdev99]

@g4titanx can I try this

[g4titanx]

@g4titanx can I try this

hey @Timosdev99 this is already part of an open pr. #331 specifically