Shared params in CLI API (#4466)

* Common shared parames getter

* Expose more types from `service-builder`

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

substrate/client/cli/src/traits.rs

@@ -15,6 +15,7 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 use structopt::{StructOpt, clap::App};
+use crate::params::SharedParams;
 
 /// Something that can augment a clap app with further parameters.
 /// `derive(StructOpt)` is implementing this function by default, so a macro `impl_augment_clap!`
@@ -37,8 +38,8 @@ macro_rules! impl_augment_clap {
 	}
 }
 
-/// Returns the log filter given by the user as commandline argument.
-pub trait GetLogFilter {
-	/// Returns the set log filter.
-	fn get_log_filter(&self) -> Option<String>;
+/// Supports getting common params.
+pub trait GetSharedParams {
+	/// Returns shared params if any.
+	fn shared_params(&self) -> Option<&SharedParams>;
 }