chore: clearer doc for list metakey

[wcy-fdu]

💦💦💦

[Xuanwo]

It's better not to touch our upgrade.md. How about polish our list_with && lister_with API docs instead?

[Xuanwo]

CI failed for doctest failed:

failures:

---- core/src/types/list.rs - types::list::Lister (line 40) stdout ----
error[E0412]: cannot find type `Entry` in this scope
 --> core/src/types/list.rs:41:18
  |
3 | let entries: Vec<Entry> = op
  |                  ^^^^^ not found in this scope
  |
help: consider importing one of these items
  |
2 + use http::header::Entry;
  |
2 + use opendal::Entry;
  |
2 + use opendal::raw::oio::Entry;
  |
2 + use reqwest::header::Entry;
  |
    and 3 other candidates

error[E0425]: cannot find value `op` in this scope
 --> core/src/types/list.rs:41:27
  |
3 | let entries: Vec<Entry> = op
  |                           ^^ not found in this scope

error[E0433]: failed to resolve: use of undeclared type `Metakey`
 --> core/src/types/list.rs:43:11
  |
5 |  .metakey(Metakey::ContentLength).await?;
  |           ^^^^^^^ use of undeclared type `Metakey`
  |
help: consider importing this enum
  |
2 + use opendal::Metakey;
  |

error[E0425]: cannot find value `entris` in this scope
 --> core/src/types/list.rs:44:14
  |
6 | for entry in entris {
  |              ^^^^^^ help: a local variable with a similar name exists: `entries`

error[E0728]: `await` is only allowed inside `async` functions and blocks
 --> core/src/types/list.rs:43:35
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_core_src_types_list_rs_40_0() {
  |                                         ----------------------------------------- this is not `async`
...
5 |  .metakey(Metakey::ContentLength).await?;
  |                                   ^^^^^ only allowed inside `async` functions and blocks

error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
 --> core/src/types/list.rs:43:40
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_core_src_types_list_rs_40_0() {
  |                                      ---------------------------------------------- this function should return `Result` or `Option` to accept `?`
...
5 |  .metakey(Metakey::ContentLength).await?;
  |                                        ^ cannot use the `?` operator in a function that returns `()`
  |
  = help: the trait `FromResidual<_>` is not implemented for `()`

error: aborting due to 6 previous errors

Some errors have detailed explanations: E0277, E0412, E0425, E0433, E0728.
For more information about an error, try `rustc --explain E0277`.
Couldn't compile the test.

failures:
    core/src/types/list.rs - types::list::Lister (line 40)

test result: FAILED. 111 passed; 1 failed; 8 ignored; 0 measured; 0 filtered out; finished in 37.97s

You can reproduce locally by running cargo test --doc

[Xuanwo]

Thanks!