fix(layer/foyers): support suffix read

[dentiny]

Which issue does this PR close?

Closes #7736

Rationale for this change

The support for suffix read feature should be decided by storage backends, and layers should panic on this feature.

What changes are included in this PR?

Change the way how full object is sliced with suffix read involved.

Are there any user-facing changes?

No.

AI Usage Statement

fable-5 helped me make the code change for me, opus-4.6 and me doing code review.

[Xuanwo]

we should remove foyer layer

[dentiny]

Hi may I ask for some context on foyer/cache layer? I, somehow, didn't find the a related open issue.
The most relevant issue might be #7107, which reads to me:

• we're working on a more general caching layer
• foyer layer should be replaced with foyer service after caching layer implemented

Currently without foyer layer, the gap seems to be we don't have a transparent caching impl?
eg, caching layer impl

let cache = HybridCacheBuilder::new()
    .memory(64 * 1024 * 1024)       // 64MB memory
    .storage()
    .build()
    .await?;
let op = Operator::new(S3::default())?
    .layer(FoyerLayer::new(cache).with_size_limit(0..10 * 1024 * 1024))
    .finish();
// transparent
let data = op.read("path/to/file").await?;

while for caching service we need to explicitly do lookaside cache

let cache_op = Operator::new(Foyer::new().memory(64 * 1024 * 1024))?.finish();
let source_op = Operator::new(S3::default())?.finish();
// lookaside cache
let data = match cache_op.read("path/to/file").await {
    Ok(data) => data,
    Err(e) if e.kind() == ErrorKind::NotFound => {
        let data = source_op.read("path/to/file").await?;
        let _ = cache_op.write("path/to/file", data.clone()).await; // best-effort fill
        data
    }
    Err(e) => return Err(e),
};

after caching layer implemented

let cache_op = Operator::new(
    Foyer::new()
        .memory(64 * 1024 * 1024)
        .disk_path("/tmp/cache")
        .disk_capacity(16 * 1024 * 1024 * 1024)
)?.finish();
let op = Operator::new(S3::default())?
    .layer(CacheLayer::new(cache_op, WholeCachePolicy::new()))
    .finish();
// transparent
let data = op.read("path/to/file").await?;

In one word, foyer layer, at least for now, still benefits?