* adding surface mem type as user arg
* adding mem type user arg for all apps
* readme update
* readme updates on all apps
[ROCm/rocdecode commit: 449572f9bf]
* code cleanup - use google style for videodecode sample and RocVideoDecoder class - no functional change
* rename SaveSurfToFile to SaveFrameToFile
[ROCm/rocdecode commit: 851c537904]