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/client/db/src/lib.rs

@@ -271,7 +271,7 @@ pub struct DatabaseSettings {
 }
 
 /// Where to find the database..
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub enum DatabaseSettingsSrc {
 	/// Load a RocksDB database from a given path. Recommended for most uses.
 	RocksDb {