Integrate radicle-artifact into explorer

- Add release read API to httpd as cargo feature enabled by default
- Add Releases and Release views to the UI
- Filter out redacted artifacts and mark delegate authors
- Degrade releases UI gracefully with older radicle-httpd versions
- Hide fully redacted releases
- Skip releases in the list endpoint when every artifact was redacted by
  its author or a delegate, so no empty release entries are shown
- Keep them reachable with showRedacted=true and by release id
- Add e2e tests for the release routes

Co-Authored-By: Rūdolfs Ošiņš <rudolfs@osins.org>

.github/workflows/check-rust.yml

@@ -54,5 +54,10 @@ jobs:
         run: cargo clippy --workspace --all-features --tests
         env:
           RUSTFLAGS: -D warnings
+      # Nothing else compiles the artifacts-off path, so it would rot.
+      - name: Run clippy on httpd without default features
+        run: cargo clippy -p radicle-httpd --no-default-features --tests
+        env:
+          RUSTFLAGS: -D warnings
       - name: Check formatting
         run: cargo fmt --all -- --check