Store the database in a role specific subdirectory (#9645)

* Store the database in a role specific subdirectory

This is a cleaned up version of #8658 fixing #6880

polkadot companion: paritytech/polkadot#2923

* Disable prometheus in tests

* Also change p2p port

* Fix migration logic

* Use different identification file for rocks and parity db

Add tests for paritydb migration

substrate/client/db/src/lib.rs

@@ -355,7 +355,7 @@ pub enum DatabaseSource {
 }
 
 impl DatabaseSource {
-	/// Return dabase path for databases that are on the disk.
+	/// Return path for databases that are stored on disk.
 	pub fn path(&self) -> Option<&Path> {
 		match self {
 			// as per https://github.com/paritytech/substrate/pull/9500#discussion_r684312550
@@ -367,6 +367,22 @@ impl DatabaseSource {
 			DatabaseSource::Custom(..) => None,
 		}
 	}
+
+	/// Set path for databases that are stored on disk.
+	pub fn set_path(&mut self, p: &Path) -> bool {
+		match self {
+			DatabaseSource::Auto { ref mut paritydb_path, .. } => {
+				*paritydb_path = p.into();
+				true
+			},
+			DatabaseSource::RocksDb { ref mut path, .. } |
+			DatabaseSource::ParityDb { ref mut path } => {
+				*path = p.into();
+				true
+			},
+			DatabaseSource::Custom(..) => false,
+		}
+	}
 }
 
 impl std::fmt::Display for DatabaseSource {