split time utils into unit

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

src/core/utils/time.rs

@@ -0,0 +1,11 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+#[inline]
+#[must_use]
+#[allow(clippy::as_conversions)]
+pub fn millis_since_unix_epoch() -> u64 {
+	SystemTime::now()
+		.duration_since(UNIX_EPOCH)
+		.expect("time is valid")
+		.as_millis() as u64
+}