Replace usage of Optional.isPresent => get => else with map-> orElseGet

I am not sure how to word this recipe or if a recipe is appropriate here, but this is a common misuse of the Optional type

• This is related to openrewrite/rewrite-static-analysis#56 but it is not quite the same

The pattern is usually:

1. Check if the value of the optional is present
2. If present, return it (or apply some transformation)
3. Else, return a default

This is effectively the same as checking if something is null and returning a default value if that's the case.

This pattern can be replaced with map followed by orElseGet

--- a/src/Util.java
+++ b/src/Util.java
@@ -40,11 +40,7 @@ public class Util {
      */
     public static Json loadFrom(final String filePath) throws IOException {
         final Optional<String> jsonContent = loadJson(filePath);
-        if(jsonContent.isPresent()) {
-            return new Json(jsonContent.get());
-        } else{
-            return new Json();
-        }
+        return jsonContent.map(Json::new).orElseGet(Json::new);
     }

Start by locating the Java recipe area responsible for Optional usage patterns and compare this request with openrewrite/rewrite-static-analysis#56. Define the supported isPresent/get/else shapes and verify that they can be expressed with map followed by orElseGet, including the transformation shown in the issue.