CSPL-3964: Adding 'go-tool-install' definition to Makefile.

Author: gabrielm-splunk

Makefile

@@ -457,4 +457,16 @@ cleanup-test-e2e:
 
 test-e2e: setup-test-e2e manifests generate fmt vet ## Run the e2e tests. Expected an isolated environment using Kind.
 	KIND_CLUSTER=$(KIND_CLUSTER) go test ./test/e2e/ -v -ginkgo.v
-	$(MAKE) cleanup-test-e2e
+	$(MAKE) cleanup-test-e2e
+
+define go-install-tool
+@[ -f "$(1)-$(3)" ] || { \
+set -e; \
+package=$(2)@$(3) ;\
+echo "Downloading $${package}" ;\
+rm -f $(1) || true ;\
+GOBIN=$(LOCALBIN) go install $${package} ;\
+mv $(1) $(1)-$(3) ;\
+} ;\
+ln -sf $(1)-$(3) $(1)
+endef