tools: Migrate remaining tools to gobin

Replace ./scripts/install_tool.sh with `gobin`, such that we have
consistent handling for all tools needed for build and consistent
versioning within ./tools/mod/go.mod.

Side changes:
  - Expose /scripts/fix.sh that fixes formatting and bom across modules
  - Expose *.sh variants of scripts like build and ./test (first step
towards replacement).
  - Make stderr output of commands explicit and make commands use
different color than callouts.

scripts/fix.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -e
+
+source ./scripts/test_lib.sh
+source ./scripts/updatebom.sh
+
+function mod_tidy_fix {
+  run rm ./go.sum || return 2
+  run go mod tidy || return 2
+}
+
+log_callout -e "\nFixing etcd code for you...\n"
+
+run_for_modules run go fmt || exit 2
+run_for_modules mod_tidy_fix || exit 2
+run_for_module tests bom_fix || exit 2
+
+log_success -e "\nSUCCESS: etcd code is fixed :)"