impl Debug for sc_service::Configuration (#6400)

* Initial commit

Forked at: 252416d385
No parent branch.

* Make sc_service::Configuration derive Debug

* Replace task_executor fn's input by proper TaskExecutor type (cleaner)

* impl From<Fn> for TaskExecutor

* Update client/cli/src/runner.rs

* Add some doc, examples and tests

* Replace Deref by fn spawn as suggested

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/primitives/database/src/lib.rs

@@ -165,6 +165,12 @@ pub trait Database<H: Clone>: Send + Sync {
 	}
 }
 
+impl<H> std::fmt::Debug for dyn Database<H> {
+	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+		write!(f, "Database")
+	}
+}
+
 /// Call `f` with the value previously stored against `key` and return the result, or `None` if
 /// `key` is not currently in the database.
 ///