feat: allow multiple added passwords

Fixes #584

common/config_builder_test.go

@@ -0,0 +1,19 @@
+package common
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParsePasswordsSplitsCommaAndWhitespace(t *testing.T) {
+	fv := &FlagVars{
+		Password:     "root,admin",
+		AddPasswords: "pass1 pass2,pass3\tpass4",
+	}
+
+	got := parsePasswords(fv)
+	want := []string{"root", "admin", "pass1", "pass2", "pass3", "pass4"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("parsePasswords() = %#v, want %#v", got, want)
+	}
+}