SelectVariableNames: use suggested name from dialect

[ZenithalHourlyRate]

This is inspired by #1219 and shares some code with #1219. This will generate more friendly backend code, for example, openfhe-pke emitter output becomes

CiphertextT dot_product(CryptoContextT cc, CiphertextT ct, CiphertextT ct1) {
  std::vector<int64_t> v = {0, 0, 0, 0, 0, 0, 0, 1};
  const auto& ct2 = cc->EvalMultNoRelin(ct, ct1);
  const auto& ct3 = cc->Relinearize(ct2);
  const auto& ct4 = cc->EvalRotate(ct3, 4);
  ...
}

CryptoContextT dot_product__generate_crypto_context() {
  CCParamsT params;
  params.SetMultiplicativeDepth(2);
  params.SetPlaintextModulus(4295294977);
  CryptoContextT cc = GenCryptoContext(params);
  cc->Enable(PKE);
  cc->Enable(KEYSWITCH);
  cc->Enable(LEVELEDSHE);
  return cc;
}

And all @heir//tests/Examples/openfhe/... pass with this change. However, other backend like Jaxite/TFHE-RS are relying on getIntForValue to properly function. I am not so familiar with them so mark as draft now.

[ZenithalHourlyRate]

However, other backend like Jaxite/TFHE-RS are relying on getIntForValue to properly function. I am not so familiar with them so mark as draft now.

Tweaked the selectVariableName process for these backend tests regarding the default prefix "v".
Namely these tests assume v0 for the first appearance then v1/v2, but for simplicity like for the openfhe backend, the crypto_context only appears once in one function so I intend to use cc instead of cc0 for it.

Ready for review now.