feat(dvc): route channels over Soft-Sync tunnels

[Marc-André Moreau (mamoreau-devolutions)]

Add DvcMessageBatch to carry a dynamic channel ID alongside its
encoded SVC messages, and validate that a Soft-Sync-selected tunnel
matches the channel before forwarding tunneled DRDYNVC data.

DrdynvcClient::process_tunnel now takes the tunnel type it was
called for and returns a DvcMessageBatch instead of a bare message
list, so a caller juggling several tunnels can route responses back
onto the correct one. disable_soft_sync_tunnel and
has_channels_on_tunnel let a caller retire a tunnel and check
whether Soft-Sync ever routed a channel onto it.

When a Soft-Sync request selects a tunnel the client does not have
available, the request is rejected outright: per MS-RDPEDYC
3.2.5.3.1 the server manager starts sending data for the selected
channels on that tunnel as soon as it sends the request, before it
sees our response, so silently omitting an unavailable tunnel from
the response would lose that inbound data.

Also includes an unrelated one-line fix in
crates/ironrdp-daemon/src/daemon.rs (separate commit): two tests
added in #1822 constructed a raw tokio::sync::mpsc::channel instead
of the OutputEventReceiver wrapper from #1815, which breaks
cargo test --workspace --locked --no-run on master for every PR
regardless of what it changes. Bundled here to unblock this PR's CI;
tracked upstream as #1830.

[Copilot]

Pull request overview

Adds Soft-Sync tunnel-aware routing for client DVC messages.

Changes:

• Introduces DvcMessageBatch.
• Validates channel-to-tunnel routing.
• Adds tunnel lifecycle APIs and tests.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
crates/ironrdp-dvc/src/lib.rs	Defines routed DVC message batches.
crates/ironrdp-dvc/src/client.rs	Implements Soft-Sync routing and tunnel handling.
crates/ironrdp-testsuite-core/tests/dvc/client.rs	Tests unavailable tunnels and batch validation.