Pending items for Pallas/Vesta <-> Bn256/Grumpkin switch

[storojs72]

This issue is a "reduction" of #1018.

#1039 performs Pallas/Vesta <-> Bn256/Grumpkin replacement in significant amount of codebase, specifically in unit-tests, which is important for generating the test-vectors, however Repl, Examples and Benchmarks are still left untouched. More specifically, following source files still use Pallas/Vesta:

<Sources>

/src/proof/nova.rs
/src/field.rs
/src/cli/mod.rs
/src/cli/field_data.rs
/src/cli/zstore.rs

<Examples>

/examples/tp_table.rs
/examples/sha256_nivc.rs
/examples/sha256_ivc.rs
/examples/circom.rs

<Benchmarks>

/benches/end2end.rs
/benches/fibonacchi.rs
/benches/public_parameters.rs
/benches/sha256.rs
/benches/common/fib.rs
/benches/synthesis.rs

Since Repl, Examples and Benchmarks are user-facing programs (and hence sensitive), it is better to have separate PR for them