expose hosterrorscache.Cache as an interface (#2291)

* expose hosterrorscache as an interface, change signature to capture the error reason

* use the hosterrorscache.CacheInterface as struct field so users of Nuclei embedded can provide their own cache implementation

Co-authored-by: Mike Rheinheimer <mrheinheimer@atlassian.com>

v2/pkg/protocols/common/hosterrorscache/hosterrorscache_test.go

@@ -1,6 +1,7 @@
 package hosterrorscache
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -9,20 +10,20 @@ import (
 func TestCacheCheckMarkFailed(t *testing.T) {
 	cache := New(3, DefaultMaxHostsCount)
 
-	cache.MarkFailed("http://example.com:80")
+	cache.MarkFailed("http://example.com:80", fmt.Errorf("no address found for host"))
 	if value, err := cache.failedTargets.Get("http://example.com:80"); err == nil && value != nil {
 		require.Equal(t, 1, value, "could not get correct number of marked failed hosts")
 	}
-	cache.MarkFailed("example.com:80")
+	cache.MarkFailed("example.com:80", fmt.Errorf("Client.Timeout exceeded while awaiting headers"))
 	if value, err := cache.failedTargets.Get("example.com:80"); err == nil && value != nil {
 		require.Equal(t, 2, value, "could not get correct number of marked failed hosts")
 	}
-	cache.MarkFailed("example.com")
+	cache.MarkFailed("example.com", fmt.Errorf("could not resolve host"))
 	if value, err := cache.failedTargets.Get("example.com"); err == nil && value != nil {
 		require.Equal(t, 1, value, "could not get correct number of marked failed hosts")
 	}
 	for i := 0; i < 3; i++ {
-		cache.MarkFailed("test")
+		cache.MarkFailed("test", fmt.Errorf("could not resolve host"))
 	}
 
 	value := cache.Check("test")