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

beacon_node/network/src/persisted_dht.rs

@@ -69,20 +69,17 @@ impl StoreItem for PersistedDht {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use sloggers::{null::NullLoggerBuilder, Build};
     use std::str::FromStr;
     use store::config::StoreConfig;
     use store::MemoryStore;
     use types::{ChainSpec, MinimalEthSpec};
     #[test]
     fn test_persisted_dht() {
-        let log = NullLoggerBuilder.build().unwrap();
         let store: HotColdDB<
             MinimalEthSpec,
             MemoryStore<MinimalEthSpec>,
             MemoryStore<MinimalEthSpec>,
-        > = HotColdDB::open_ephemeral(StoreConfig::default(), ChainSpec::minimal().into(), log)
-            .unwrap();
+        > = HotColdDB::open_ephemeral(StoreConfig::default(), ChainSpec::minimal().into()).unwrap();
         let enrs = vec![Enr::from_str("enr:-IS4QHCYrYZbAKWCBRlAy5zzaDZXJBGkcnh4MHcBFZntXNFrdvJjX04jRzjzCBOonrkTfj499SZuOh8R33Ls8RRcy5wBgmlkgnY0gmlwhH8AAAGJc2VjcDI1NmsxoQPKY0yuDUmstAHYpMa2_oxVtw0RW_QAdpzBQA8yWM0xOIN1ZHCCdl8").unwrap()];
         store
             .put_item(&DHT_DB_KEY, &PersistedDht { enrs: enrs.clone() })