Overhaul database package

go/database/setup_test_db.sql

+# SQL for setting up the test database and user.
+CREATE DATABASE IF NOT EXISTS sk_testing;
+GRANT ALL ON sk_testing.* TO 'test_root'@'localhost';
+GRANT SELECT,INSERT,UPDATE,DELETE ON sk_testing.* TO 'test_rw'@'localhost';
+
+# SkiaPerf database.
+CREATE DATABASE IF NOT EXISTS skia;
+GRANT SELECT,INSERT,UPDATE,DELETE ON skia.* TO 'readwrite'@'localhost';
+
+# SkiaGold database.
+CREATE DATABASE IF NOT EXISTS skiacorrectness;
+GRANT SELECT,INSERT,UPDATE,DELETE ON skiacorrectness.* TO 'readwrite'@'localhost';
+
+# Buildbot database.
+CREATE DATABASE IF NOT EXISTS buildbot;
+GRANT SELECT,INSERT,UPDATE,DELETE ON buildbot.* TO 'readwrite'@'localhost';