Update on "[#9971] Gracefully error out in ETDump for get_flatbuffer_scalar_type"

Following #9971

- Update get_flatbuffer_scalar_type return type to Result<T>
- Iteratively update functions that calling the functions with result type changed:
  - Check returns, if with an error, pass above the error.
  - If unable to pass error, update the return type as Result<T>

Differential Revision: [D72771753](https://our.internmc.facebook.com/intern/diff/D72771753/)

[ghstack-poisoned]

Author: zhenyanzhang

runtime/core/event_tracer.h

@@ -313,6 +313,9 @@ class EventTracer {
    * @param[in] evalue The value to be logged.
    * @param[in] evalue_type Indicates what type of output this is logging e.g.
    * an intermediate output, program output etc.
+   * @return A Result<bool> indicating the status of the logging operation.
+   *         - True if the evalue output was successfully logged.
+   *         - An error code if an error occurs during logging.
    */
   virtual Result<bool> log_evalue(
       const EValue& evalue,