Simplify test coverage collection (#2560)

* Simplify test coverage script by running go test command

Signed-off-by: Pankhudi Bhonsle <pankhubh@thoughtworks.com>

* Modify coverage make task to take coverprofile flag

Signed-off-by: Pankhudi Bhonsle <pankhubh@thoughtworks.com>

* Remove pre-compilation of test and TODO comment

Signed-off-by: Pankhudi Bhonsle <psbhonsle08@gmail.com>

Co-authored-by: Pankhudi Bhonsle <pankhubh@thoughtworks.com>

Makefile

@@ -150,10 +150,7 @@ all-srcs:
 
 .PHONY: cover
 cover: nocover
-	@echo pre-compiling tests
-	@time go test -i $(shell go list ./...)
-	# TODO Switch to single `go test` that already supports multiple packages, but watch out for .nocover dirs.
-	@./scripts/cover.sh $(shell go list ./...)
+	$(GOTEST) -coverprofile cover.out ./...
 	grep -E -v 'model.pb.*.go' cover.out > cover-nogen.out
 	mv cover-nogen.out cover.out
 	go tool cover -html=cover.out -o cover.html