internal/component: Move Pool into lazy package

pkg/lazy/lazy_test.go

@@ -0,0 +1,31 @@
+package lazy
+
+import "fmt"
+
+func ExampleLazy() {
+
+	var lazy Lazy[int]
+
+	// the first invocation to lazy will be called and set the value
+	fmt.Println(lazy.Get(func() int { return 42 }))
+
+	// the second invocation will not call init again, using the first value
+	fmt.Println(lazy.Get(func() int { return 43 }))
+
+	// Set can be used to set a specific value
+	lazy.Set(0)
+	fmt.Println(lazy.Get(func() int { panic("never called") }))
+
+	// Output: 42
+	// 42
+	// 0
+}
+
+func ExampleLazy_nil() {
+	var lazy Lazy[int]
+
+	// passing nil as the initialization function causes the zero value to be set
+	fmt.Println(lazy.Get(nil))
+
+	// Output: 0
+}