bitfield dist logging cleanup and enhancements (#5147)

* split metrics from bitfield signing

* cleanup all logging

* add a unit test for subset generation

* chore: add one more test to assert need is properly represented

* u8 as usize

* chore: overseer fixin

* fix test

* Update node/network/bitfield-distribution/src/metrics.rs

Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>

* Update node/network/bitfield-distribution/src/metrics.rs

Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>

* fallout from suggested rename

* consistency

Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>

polkadot/node/subsystem-util/src/tests.rs

@@ -245,3 +245,14 @@ fn tick_tack_metronome() {
 		)
 	});
 }
+
+#[test]
+fn subset_generation_check() {
+	let values = (0_u8..=25).collect::<Vec<_>>();
+	// 12 even numbers exist
+	let mut chosen = choose_random_subset::<u8, _>(|v| v & 0x01 == 0, values, 12);
+	chosen.sort();
+	for (idx, v) in dbg!(chosen).into_iter().enumerate() {
+		assert_eq!(v as usize, idx * 2);
+	}
+}