Add log debounce to work processor (#3045)

## Issue Addressed

#3010 

## Proposed Changes

- move log debounce time latch to `./common/logging`
- add timelatch to limit logging for `attestations_delay_queue` and `queued_block_roots`

## Additional Info

- Is a separate crate for the time latch preferred? 
- `elapsed()` could take `LOG_DEBOUNCE_INTERVAL ` as an argument to allow for different granularity.

common/logging/src/lib.rs

@@ -7,9 +7,13 @@ use lighthouse_metrics::{
 use slog::Logger;
 use slog_term::Decorator;
 use std::io::{Result, Write};
+use std::time::{Duration, Instant};
 
 pub const MAX_MESSAGE_WIDTH: usize = 40;
 
+/// The minimum interval between log messages indicating that a queue is full.
+const LOG_DEBOUNCE_INTERVAL: Duration = Duration::from_secs(30);
+
 lazy_static! {
     pub static ref INFOS_TOTAL: MetricsResult<IntCounter> =
         try_create_int_counter("info_total", "Count of infos logged");
@@ -187,6 +191,25 @@ fn is_ascii_control(character: &u8) -> bool {
     )
 }
 
+/// Provides de-bounce functionality for logging.
+#[derive(Default)]
+pub struct TimeLatch(Option<Instant>);
+
+impl TimeLatch {
+    /// Only returns true once every `LOG_DEBOUNCE_INTERVAL`.
+    pub fn elapsed(&mut self) -> bool {
+        let now = Instant::now();
+
+        let is_elapsed = self.0.map_or(false, |elapse_time| now > elapse_time);
+
+        if is_elapsed || self.0.is_none() {
+            self.0 = Some(now + LOG_DEBOUNCE_INTERVAL);
+        }
+
+        is_elapsed
+    }
+}
+
 /// Return a logger suitable for test usage.
 ///
 /// By default no logs will be printed, but they can be enabled via