Make optional.Option[T] type serializable (#29282)

make the generic `Option` type de-/serializable for json and yaml

---------

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
(cherry picked from commit 53c7d8908e5ef35818b72b8c3d873b509269bc1a)

modules/optional/option_test.go

@@ -1,47 +1,49 @@
 // Copyright 2024 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
-package optional
+package optional_test
 
 import (
 	"testing"
 
+	"code.gitea.io/gitea/modules/optional"
+
 	"github.com/stretchr/testify/assert"
 )
 
 func TestOption(t *testing.T) {
-	var uninitialized Option[int]
+	var uninitialized optional.Option[int]
 	assert.False(t, uninitialized.Has())
 	assert.Equal(t, int(0), uninitialized.Value())
 	assert.Equal(t, int(1), uninitialized.ValueOrDefault(1))
 
-	none := None[int]()
+	none := optional.None[int]()
 	assert.False(t, none.Has())
 	assert.Equal(t, int(0), none.Value())
 	assert.Equal(t, int(1), none.ValueOrDefault(1))
 
-	some := Some[int](1)
+	some := optional.Some[int](1)
 	assert.True(t, some.Has())
 	assert.Equal(t, int(1), some.Value())
 	assert.Equal(t, int(1), some.ValueOrDefault(2))
 
 	var ptr *int
-	assert.False(t, FromPtr(ptr).Has())
+	assert.False(t, optional.FromPtr(ptr).Has())
 
 	int1 := 1
-	opt1 := FromPtr(&int1)
+	opt1 := optional.FromPtr(&int1)
 	assert.True(t, opt1.Has())
 	assert.Equal(t, int(1), opt1.Value())
 
-	assert.False(t, FromNonDefault("").Has())
+	assert.False(t, optional.FromNonDefault("").Has())
 
-	opt2 := FromNonDefault("test")
+	opt2 := optional.FromNonDefault("test")
 	assert.True(t, opt2.Has())
 	assert.Equal(t, "test", opt2.Value())
 
-	assert.False(t, FromNonDefault(0).Has())
+	assert.False(t, optional.FromNonDefault(0).Has())
 
-	opt3 := FromNonDefault(1)
+	opt3 := optional.FromNonDefault(1)
 	assert.True(t, opt3.Has())
 	assert.Equal(t, int(1), opt3.Value())
 }