feat: use gotestsum for unit tests when available

[vdemeester]

Changes

Use gotestsum in make test-unit when available, falling back to go test otherwise. This follows the same pattern as pipelines-as-code.

gotestsum provides improved test output formatting. The default format is testdox which gives a readable sentence for each test:

 ✓ Workspace binding validate valid (0.00s)
 ✓ Workspace binding validate invalid (0.00s)

DONE 1248 tests in 0.203s

The format can be overridden via the DEFAULT_GOTESTSUM_FORMAT variable:

make test-unit DEFAULT_GOTESTSUM_FORMAT=pkgname

Available formats:

Format	Description
dots	Print a character for each test
dots-v2	Dots format, one package per line
pkgname	Print a line for each package (gotestsum default)
pkgname-and-test-fails	Line per package and failed test output
testname	Print a line for each test and package
testdox	Print a sentence for each test (Makefile default)
github-actions	testname with GitHub Actions log grouping
standard-quiet	Standard go test format
standard-verbose	Standard go test -v format

DEVELOPMENT.md is updated to document gotestsum as an optional tool and describe the available formats.

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Release Notes

NONE

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[chmouel]

/lgtm

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In response to this:

/lgtm

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[chmouel]

or add it to your .envrc as export DEFAULT_GOTESTSUM_FORMAT=foo to make it permanent