Box filter padding updates

[Srihari-mcw]

• Adds nearest neighbors padding for box filter augmentation (Current ToT version had border pixels fading out, the PR attempts to fix the same )
• Separated the compute functions of all bit depths on both HOST and HIP Backends (Avoids additional bit depth conversions)
• Templated the compute functions for all filter sizes into one on the HIP Backend which improves/reduces lines of code significantly

[rrawther]

@AryanSalmanpour : Can you please review the HIP code for this PR

[LakshmiKumar23]

@spolifroni-amd can you fix the docs issue. This is blocking our merge