feat: add a test macro

[twuebi]

1. Added a test macro #[minio_macros::test], it performs setup and tear down for tests (currently creation + deletion of bucket), if no bucket is wished #[minio_macros::test(no_bucket)] will be your friend. If the test panics, it'll catch the unwind and attempt cleanup before resuming the unwind.
2. replace some blocking io in tests with async_std variants

[donatello]

@twuebi Please fix conflicts

[twuebi]

I'm still tracking down some functions that seem to take too long between await points leading to some really slow/hanging tests when running on the standard tokio runtime (https://ryhl.io/blog/async-what-is-blocking/). I think our impl Stream for RandSrc may be the culprit, calls to poll_next take anything between 200 - 800 microseconds, will have to look a bit more into it.

[HJLebbink]

LGTM, thanx for cleaning up!

[Copilot]

Pull Request Overview

This PR refactors the test suite and some client utility functions to adopt a new asynchronous testing approach by replacing the traditional #[tokio::test] attribute with a custom #[minio_macros::test] macro and switching blocking IO operations to async_std variants.

• Replaces tokio test attributes with the new custom test macro that supports bucket setup/cleanup and express mode skipping.
• Converts blocking file operations to async_std counterparts and updates related functions to use Arc for improved async behavior.
• Updates environment variable references and adjusts benchmarks and cleanup logic accordingly.

Reviewed Changes

Copilot reviewed 42 out of 42 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/*.rs	Refactored tests to use async_std and the new test macro; adjusted test signatures and environment variable usage.
src/s3/utils.rs, src/s3/types.rs	Updated APIs to use Arc for SegmentedBytes and improved async compatibility.
src/s3/client.rs	Adapted client methods to spawn blocking tasks for SHA256 hashing and use Arc for body handling.
macros/	Introduced the custom test attribute macro enhancing test setup and cleanup.
common/	Updated environment variable references and asynchronous bucket cleanup.
benches/	Adjusted environment variable usage and minor code style improvements.

Comments suppressed due to low confidence (2)

common/src/rand_src.rs:49

• The read chunk size has been reduced from 64 KiB to 8 KiB. Confirm that this smaller chunk size is intentional as it may affect performance when reading large amounts of data.

        let bytes_read = self.size.min(8 * 1024) as usize;

src/s3/client.rs:452

• [nitpick] Using async_std::task::spawn_blocking for SHA256 hashing offloads the computation but may introduce overhead when invoked frequently. Review the performance impact under high load to ensure it meets your throughput requirements.

                        }

[donatello]

LGTM - thanks for adding the current_thread/multi_thread tests!

[HJLebbink]

LGTM