Enable user to set QNN HTP performance mode for every session run (#19521)
### Description
Currently, the QNN HTP performance mode is set during session creation, there's no way to change it afterwards. There's requirement to set it high performance mode for high priority request and set it back to low performance mode later to save the power when the incoming request is idle for example.
Now, still keeps the performance mode at the session level in QNN EP options which is used at the default one. Ort QNN EP will set it once if user set it.
And there are setting (qnn.htp_perf_mode and qnn.htp_perf_mode_post_run) in run option to change the performance mode before and after session run. There's recommended scenario that user set the mode to high performance mode before the the inference sun so that user can get the result back ASAP. And set the mode to low performance mode after the inference to save the power.