Integrate tracing (#6339)

Tracing Integration
- [reference](5bbf1859e9/projects/project-ideas.md (L297))


  - [x] replace slog & log with tracing throughout the codebase
- [x] implement custom crit log
- [x] make relevant changes in the formatter
- [x] replace sloggers
- [x] re-write SSE logging components

cc: @macladson @eserilev

lcli/src/transition_blocks.rs

@@ -72,8 +72,6 @@ use eth2::{
     BeaconNodeHttpClient, SensitiveUrl, Timeouts,
 };
 use eth2_network_config::Eth2NetworkConfig;
-use log::{debug, info};
-use sloggers::{null::NullLoggerBuilder, Build};
 use ssz::Encode;
 use state_processing::state_advance::complete_state_advance;
 use state_processing::{
@@ -87,6 +85,7 @@ use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::{Duration, Instant};
 use store::HotColdDB;
+use tracing::{debug, info};
 use types::{BeaconState, ChainSpec, EthSpec, Hash256, SignedBeaconBlock};
 
 const HTTP_TIMEOUT: Duration = Duration::from_secs(10);
@@ -196,14 +195,8 @@ pub fn run<E: EthSpec>(
      * Create a `BeaconStore` and `ValidatorPubkeyCache` for block signature verification.
      */
 
-    let store = HotColdDB::open_ephemeral(
-        <_>::default(),
-        spec.clone(),
-        NullLoggerBuilder
-            .build()
-            .map_err(|e| format!("Error on NullLoggerBuilder: {:?}", e))?,
-    )
-    .map_err(|e| format!("Failed to create ephemeral store: {:?}", e))?;
+    let store = HotColdDB::open_ephemeral(<_>::default(), spec.clone())
+        .map_err(|e| format!("Failed to create ephemeral store: {:?}", e))?;
     let store = Arc::new(store);
 
     debug!("Building pubkey cache (might take some time)");