Replace lodash with built-ins where possible to reduce bundle size (#1766)

* add tslint rule to disallow lodash.isUndefined

* add tslint rule to disallow lodash.isNull

* apply fixes

packages/ethereum-types/package.json

@@ -12,6 +12,7 @@
         "build:ci": "yarn build",
         "clean": "shx rm -rf lib generated_docs",
         "lint": "tslint --format stylish --project .",
+        "fix": "tslint --fix --format stylish --project .",
         "docs:json": "typedoc --excludePrivate --excludeExternals --target ES5 --tsconfig typedoc-tsconfig.json --json $JSON_FILE_PATH $PROJECT_FILES"
     },
     "config": {