Add time flag in kapp

[Dhananjhay]

The kapp CLI currently lacks a --time flag and defaults to allocating 1 hour for building an image. While this duration works well for small to medium-sized images, it often falls short for larger images likedocker://micalab/micapipe:v0.2.3, where more time is needed to complete the pull and build processes. Adding a --time flag would allow users greater flexibility when working with larger images.

The --time flag would accept an integer input representing hours (e.g., [x:int]:00). Given that building an image rarely requires more than 24 hours, limiting the time allocation to hours should be sufficient for all use cases, including those with extensive build requirements.

[pvandyken]

I'm fine with this, thanks!