chore: bump hyperlight-* dependencies to 0.16.0 (#517)

* chore: bump hyperlight-* dependencies to 0.16.0

hyperlight-host 0.16.0 publishes the OCI-format snapshot save/load API
(PR #1465) that downstream integrators need for cross-host snapshot
persistence. Tracking that release here so the wasm wrapper exposes the
new Snapshot surface unchanged.

Signed-off-by: Yordis Prieto <yordis.prieto@gmail.com>

* fix(wasm_sandbox): drop trailing None from map_file_cow call

hyperlight-host 0.16.0 dropped the third `Option` argument on
`MultiUseSandbox::map_file_cow`. Without this fix the bump to
host 0.16 fails to compile with E0061 unexpected argument.

Signed-off-by: Yordis Prieto <yordis.prieto@gmail.com>

* feat(wasm): re-export OciTag, OciReference, OciDigest from snapshot

These types are needed to call `Snapshot::save` / `Snapshot::load` from
downstream crates that consume `hyperlight-wasm` directly. Without the
re-export they sit in `hyperlight_host::sandbox::snapshot`, a private
module path that downstream cannot reach without taking a direct
dependency on `hyperlight-host` (which defeats the purpose of the
wasm wrapper crate).

Signed-off-by: Yordis Prieto <yordis.prieto@gmail.com>

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Signed-off-by: Yordis Prieto <yordis.prieto@gmail.com>

Author: yordis