1. Fix pools integration test to avoid occasional deadlocks
2. tmtc module: The `CcsdsPacketHandler` and `PusServiceProvider`
do not require a send bound anymore. However, these traits now
have an extension trait called `Sendable<DefaultName>` which requires
the trait + Send. A blanket implementation is provided. The helper
structs like `PusDistributor` and `CcsdsDistributor` require
the new Sendable trait version to allow more ergnomic usage
with threads.
