Fix Snyk vulnerabilities (#1078)

This PR fixes most of the Snyk vulnerabilities in the `static/package-lock.json`. Specifically, it addresses some or all of the vulnerabilities from the following packages by upgrading their patch or minor versions: `object-path`, `grunt`, `underscore.string`, `postcss`, `ansi-regex`, `async`, `nth-check`, `json-schema`, `ajv`, `browserslist`, `path-parse`, `ws`, `nanoid`, `minimist`, and `uglify-js`.

J=none
TEST=manual

After this PR is merged into develop, will check to make sure the vulnerabilities are no longer in Snyk.