Benching utility for deno_core op system

Example:

```rust use denobenchutil::benchorprofile; use denobenchutil::bencher::{benchmarkgroup, Bencher}; use denobenchutil::benchjs_sync};

use denocore::opsync; use denocore::serializeopresult; use denocore::Extension; use denocore::JsRuntime; use denocore::Op; use deno_core::OpState;

fn setup() -> Vec { let customext = Extension::builder() .ops(vec![ ("opnop", |state, | { Op::Sync(serializeop_result(Ok(9), state)) }), ]) .build();

vec![ // deno{ext}::init(...), customext, ] }

fn benchopnop(b: &mut Bencher) { benchjssync(b, r#"Deno.core.ops.op_nop();"#, setup); }

benchmarkgroup!(benches, benchopnop); benchor_profile!(benches); ```