test(log): add comprehensive benchmarks

Adds a new benchmark_test.go file with comprehensive benchmarks for the logging library:

Serial benchmarks:
- Trace, Debug, Info, Notice, Warn, Error levels

Formatted logging:
- Debugf, Infof, Errorf variants

Parallel benchmarks:
- DebugParallel, InfoParallel, InfofParallel

Logger instance (namespaced):
- LoggerInfo, LoggerInfof, LoggerDebugParallel

Multiple clients/namespaces:
- MultipleClients, MultipleNamespaces

Message size comparison:
- Short, Medium, Long messages

Level filtering overhead:
- DebugFilteredByLevel

Also removes the duplicate BenchmarkDebugSerial from log_test.go and applies minor whitespace formatting fixes.

Fixes #6

log/log_test.go

@@ -2,7 +2,6 @@ package log
 
 import (
 	"strconv"
-	"sync"
 	"testing"
 )
 
@@ -37,21 +36,6 @@ func TestSetLogLevel(t *testing.T) {
 	c.Destroy()
 }
 
-func BenchmarkDebugSerial(b *testing.B) {
-	c := CreateClient("test")
-	var x sync.WaitGroup
-	x.Add(b.N)
-	for i := 0; i < b.N; i++ {
-		Debug(i)
-		go func() {
-			c.Get()
-			x.Done()
-		}()
-	}
-	x.Wait()
-	c.Destroy()
-}
-
 // Trace ensure logs come out in the right order
 func TestOrder(t *testing.T) {
 	testString := "Testing trace: "