Logrus hooks for terminal vs log-file output (#16102)

## Review after #16059 

**What type of PR is this?**
Feature

**What does this PR do?**
This PR introduces logrus writer hooks into the logging of prysm.
when log-format is text:
- set the default logrus output to be `io.Discard`
- create a writer hook for terminal, with formatting and coloring
enabled.
- create a separate writer hook for log-file (if enabled), without
coloring.

This immediately allows for having formatted/colored terminal logs,
while keeping the log-file clean.

cmd/client-stats/main.go

@@ -86,7 +86,7 @@ func main() {
 
 		logFileName := ctx.String(cmd.LogFileName.Name)
 		if logFileName != "" {
-			if err := logs.ConfigurePersistentLogging(logFileName); err != nil {
+			if err := logs.ConfigurePersistentLogging(logFileName, format); err != nil {
 				log.WithError(err).Error("Failed to configuring logging to disk.")
 			}
 		}