feat: add STATIC, CACHED reasons (#360)

As per:
https://github.com/open-feature/spec/blob/7ed7442c40d4e766424671258846b21a96adda70/specification/types.md#resolution-details

Signed-off-by: Todd Baert <[email protected]>

Author: toddbaert

src/types.ts

@@ -300,6 +300,16 @@ export const StandardResolutionReasons = {
    * The reason for the resolved value could not be determined.
    */
   UNKNOWN: 'UNKNOWN',
+  
+  /**
+   * The resolved value is static (no dynamic evaluation).
+   */
+  STATIC: 'STATIC',
+  
+  /**
+   * The resolved value was retrieved from cache.
+   */
+  CACHED: 'CACHED',
 
   /**
    * The resolved value was the result of an error.