* Update changelog for v1.0.0-beta.7
* Increment all crate versions
* Remove redundant release test that is now covered by CI
* Remove completed NU5 README check task from the release template
* Add Merge Freeze tool to the release checklist
* Simplify release checklist by removing unused steps
* Create new empty `zebra-node-services` crate
The goal is to store the mempool `Request` and `Response` types so that
the `zebra-rpc` crate can interface with the mempool service without
having to import `zebrad`.
* Move `Gossip` mempool type into new crate
It is required by the `Request` type, which will be moved next.
* Add documentation to `Gossip` variants
Avoid having to add an exception to allow undocumented code.
* Move `mempool::Request` type to new crate
The first part of the service interface definition. Usages have been
changed to refer to the new crate directly, and since this refactor is
still incomplete, some `mp` aliases are used in a few places to refer to
the old module.
* Create an `UnboxMempoolError` helper trait
Centralize some common code to extract and downcast boxed mempool
errors. The `mempool::Response` will need to contain a `BoxError`
instead of a `MempoolError` when it is moved to the
`zebra-node-services` crate, so this prepares the tests to be updated
with less changes.
* Use `UnboxMempoolError` in tests
Make the necessary changes so that the tests are ready to support a
`BoxError` in the `mempool::Response` type.
* Use `BoxError` in `mempool::Response`
Prepare it to be moved to the `zebra-node-services` crate.
* Move `mempool::Response` to `zebra-node-services`
Update usages to import from the new crate directly.
* Remove `mp` aliases for mempool component module
Use any internal types directly instead.
* Replace `tower::BoxService` with custom alias
Remove the dependency of `zebra-node-services` on `tower`.
* Move `Gossip` into a separate `sub-module`
Keep only the main `Request` and `Response` types in the `mempool`
module.
* Use `crate::BoxError` instead of `tower::BoxError`
Follow the existing convention.
* Add missing `gossip.rs` module file
It was missing from a previous refactor commit.