Hackless Go-native tools for Knative

The productivity consensus is to deprecate the hacks repository and shift away from using shell scripts in Knative. Instead, the well-defined functionality should be re-implemented using Go-native tools. This will make it easier for Knative contributors to maintain, allow for testing with ease, and ultimately improve the overall solution's quality.

The default target for this rewrite is the [knative/toolbox](https://github.com/knative/toolbox) repository. Some code, which is reusable and might be used by direct code import, might be rewritten to specific sub-package withing the [knative.dev/pkg](https://pkg.go.dev/knative.dev/pkg).

## Task list

- [ ] knative/toolbox#16
- [ ] knative/toolbox#17
- [ ] knative/toolbox#18
- [ ] knative/toolbox#19
- [ ] knative/toolbox#20
- [ ] knative/toolbox#21
- [ ] Deprecate knative/hack

## Original issue by @kvmware:

> It has gotten to a point where hack scripts are more than what they should be doing in bash.
> We should minimize the amount of bash to simple easy to understand shellchecked bash scripts and offload any more complicated logic to golang which the community has more familiarity with.