RFC-2299: Chain based Operator API

[Xuanwo]

This proposal will add chain based API for Operator and BlockingOperator:

from

let bs = op.read_with(
  "path/to/file",
  OpRead::new()
    .with_range(0..=1024)
    .with_if_match("<etag>")
    .with_if_none_match("<etag>")
    .with_override_cache_control("<cache_control>")
    .with_override_content_disposition("<content_disposition>")
  ).await?;

to

let bs = op.read_with("path/to/file")
  .range(0..=1024)
  .if_match("<etag>")
  .if_none_match("<etag>")
  .override_cache_control("<cache_control>")
  .override_content_disposition("<content_disposition>")
  .await?;

[suyanhanx]

Why not just merge read_with into read?

[Xuanwo]

Why not just merge read_with into read?

Becuase blocking API can't merge, we don't want to provide API like:

let bs = op.read("path/to/file").call()?;

[PsiACE]

lgtm

[suyanhanx]

I would like to hear more from the community.