Add manual neutral models for java.text.Format and java.text.MessageFormat

See comment in java/ql/src/Metrics/Summaries/TopJdkApis.qll

   * Note: the following top JDK APIs are not modeled with MaD:
   * `java.text.Format#format(Object)`: similar issue as `Object.toString`; depends on the object being passed as the argument
   * `java.text.MessageFormat#format(String,Object[])`: similar issue as `Object.toString`; depends on the object being passed as the argument

Author: owen-mc

java/ql/lib/ext/java.text.model.yml

@@ -3,6 +3,9 @@ extensions:
       pack: codeql/java-all
       extensible: neutralModel
     data:
+      - ["java.text", "Format", "format", "", "summary", "manual"]        # similar issue as `Object.toString`; depends on the object being passed as the argument
+      - ["java.text", "MessageFormat", "format", "", "summary", "manual"] # similar issue as `Object.toString`; depends on the object being passed as the argument
+
       # summary neutrals
       # The below APIs have numeric flow and are currently being stored as neutral models.
       # These may be changed to summary models with kinds "value-numeric" and "taint-numeric" (or similar) in the future.