Validate denoiser executable

Currently the Plugin does not check if the executable is the right one.

oidnDenoise.exe - Is correct and works.
oidnBenchmark.exe - Is invalid and only throws an `Error: invalid argument` in the debug console. Also locks up the Renderer.
oidnTest.exe - Is invalid and nothing happens.
DiskInfo64.exe - Is invalid and nothing happens.

---

Owing to how Chunky responded to `oidnBenchmark.exe` and `Error: invalid argument` I would recommend that we actually validate if the provided executable is the right one. Running `oidnDenoise.exe` or `oidnDenoise.exe -h` would show a list of valid command-line options.
```
D:\Programs\oidn-1.4.2.x64.vc14.windows\bin>oidnDenoise.exe
Intel(R) Open Image Denoise
usage: oidnDenoise [-d/--device default|cpu]
[-f/--filter RT|RTLightmap]
[--hdr color.pfm] [--ldr color.pfm] [--srgb] [--dir directional.pfm]
[--alb albedo.pfm] [--nrm normal.pfm] [--clean_aux]
[--is/--input_scale value]
[-o/--output output.pfm] [-r/--ref reference_output.pfm]
[-t/--type float|half]
[-w/--weights weights.tza]
[--threads n] [--affinity 0|1] [--maxmem MB] [--inplace]
[--bench ntimes] [-v/--verbose 0-3]
[-h/--help]
```

While the exact contents of the return may change we could still check and validate some of these results.