plaid-link: Add linkCustomizationName to CreateConfig (#42725)

Plaid Link now accepts a linkCustomizationName, user-defined on their dashboard,
 and passed in the CreateConfig.

types/plaid-link/index.d.ts

@@ -24,6 +24,7 @@ export namespace Plaid {
         onEvent?: OnEvent;
         onLoad?: OnLoad;
         language?: Language;
+        linkCustomizationName?: string;
         countryCodes?: Country[];
         webhook?: string;
         userLegalName?: string;