Added Application XnConvert

[SHR1SHAK]

XnConvert is a fast, powerful and free cross-platform batch image converter. Its fast and can handle any type of image file format conversion. https://www.xnview.com/en/xnconvert/

[SHR1SHAK]

Thanks for the suggestion @og-mrk.

[SHR1SHAK]

I have also fixed the choco repo link as I got confused and inserted another of xn product but its fixed.

[SHR1SHAK]

Thanks you @og-mrk

[ChrisTitusTech]

Not accepting any more programs at this time. We will be moving most of the "niche" programs into a button utilizing UniGetUI.