Replace "go test" with "gotestsum" in Makefile

[zalegrala]

What this PR does:

Here is a proposal to use gotestsum in place of go test for the purpose of improving the output of the test results. Color adds a lot of context, and the particular format chosen here is one of many available.

• Create tools/ package and add initial go.mod
• Imports new make targets for installing tools from sub directory
• Include the tools target as a make dependency in several CI job tasks
• Propose structure to support additional CI tools in the future, managed as go dependencies in tools/

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[zalegrala]

Alternative to the make target dependency here, we could add make tools in the CI as a step.

[zalegrala]

I thought this was a good time to start breaking up the make config a bit, but if we like it all in one, I can move these targets into the Makefile.

[zalegrala]

The ALL_PKGS variable is empty for some reason and I've not looked why.

[zalegrala]

Feel free to review a test run here, as the output will be noticeable.

[joe-elliott]

i like this. one question below. also can we add golangci-lint and jsonnetfmt to the tools list?

does gofmt come with go? or should we add that to?

[zalegrala]

I agree other tools can be slotted in here, perhaps in a follow up PR. I like gofumpt from https://github.com/mvdan/gofumpt but we should chat before introducing it unless we make it automatic. See my slack comment from earlier today :)

[electron0zero]

q: why gotest.tools, and why not github? imo, I would trust github over gotest.tools to not serve me a bad or compromised verison of gotestsum :)

[zalegrala]

Not really sure, but its in their recommendation for go install, so that's what I'd put here.

[zalegrala]

And indeed their module is gotest.tools also.

[zalegrala]

Merged, since this wasn't a blocking comment, but if we want to discuss and revisit I'm open to it.