Feature Request: tkn debug

While there are certainly features of tkn that aid with debugging a TaskRun or PipelineRun, there isn't, in my opinion, something similar to the experience of using an IDE debugger when both developing Tekton resources (e.g. pipelines/tasks) and figuring out what is wrong with an already developed Tekton resource.

I imagine this feature having the following requirements:

1. Ability to pause and restart pipelines/tasks before or after a task in the case of a pipeline or a step in the case of a task. Think of this as a breakpoint in an IDE.
2. The ability to see the values of variables when a pipeline/task stops at a breakpoint.
3. It would be nice to be able to do all of these actions from an IDE. This is obviously not a requirement for the CLI, but tkn would likely be used by any IDE that wishes to implement this experience. So it's something that should be kept in mind.

As mentioned previously, I think there are two use cases where I see this making sense:
Development - Actually developing pipelines/tasks. The ability to have a similar debugging experience to what developers are familiar with when developing applications I think would greatly help developers actually create CI/CD resources.
Management - Helping teams figure out what has caused a pipeline/task that is actually used for a development process to break.

I do not have any hard opinions on how this could be implemented from a user experience perspective from the CLI. I think this issue can be used to help further define this feature and discuss ideas.

/kind feature

The issue names no files, tests, or implementation entry points. Start by reviewing the existing tkn debugging commands and Tekton TaskRun and PipelineRun capabilities, then clarify the breakpoint, variable inspection, and restart requirements. Done means an agreed feature scope and implementation design rather than a single scoped change.