refactor for stronger RawPduId type

implement standard traits for PduCount

enable serde for arrayvec

typedef various shortid's

pducount simplifications

split parts of pdu_metadata service to core/pdu and api/relations

remove some yields; improve var names/syntax

tweak types for limit timeline limit arguments

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/pdu/tests.rs

@@ -0,0 +1,19 @@
+#![cfg(test)]
+
+use super::PduCount;
+
+#[test]
+fn backfilled_parse() {
+	let count: PduCount = "-987654".parse().expect("parse() failed");
+	let backfilled = matches!(count, PduCount::Backfilled(_));
+
+	assert!(backfilled, "not backfilled variant");
+}
+
+#[test]
+fn normal_parse() {
+	let count: PduCount = "987654".parse().expect("parse() failed");
+	let backfilled = matches!(count, PduCount::Backfilled(_));
+
+	assert!(!backfilled, "backfilled variant");
+}