Optimize processing of slashings (#14990)

* Calculate max epoch and churn for slashing once

* calculate once for proposer and attester slashings

* changelog <3

* introduce struct

* check if err is nil in ProcessVoluntaryExits

* rename exitData to exitInfo and return from functions

* cleanup + tests

* cleanup after rebase

* Potuz's review

* pre-calculate total active balance

* remove `slashValidatorFunc` closure

* Avoid a second validator loop

    🤖 Generated with [Claude Code](https://claude.ai/code)

    Co-Authored-By: Claude <noreply@anthropic.com>

* remove balance parameter from slashing functions

---------

Co-authored-by: terence tsao <terence@prysmaticlabs.com>
Co-authored-by: potuz <potuz@prysmaticlabs.com>

runtime/logging/logrus-prefixed-formatter/README.md

@@ -35,8 +35,8 @@ Here is how it should be used:
 package main
 
 import (
-	"github.com/sirupsen/logrus"
 	prefixed "github.com/prysmaticlabs/prysm/runtime/logging/logrus-prefixed-formatter"
+	"github.com/sirupsen/logrus"
 )
 
 var log = logrus.New()