Implement <Conditional> ujsx component with test prop (string/function), else prop, and unit tests

src/component/index.ts

@@ -1,3 +1,5 @@
+export { Conditional } from "./conditional.js";
+export type { ConditionalProps } from "./conditional.js";
 export { Operation } from "./operation.js";
 export type { OperationProps } from "./operation.js";
 export { Parallel } from "./parallel.js";