src/vs/platform/log/common/log.ts/parseLogLevel
export function parseLogLevel(logLevel: string): LogLevel | undefined {
	switch (logLevel) {
		case 'trace':
			return LogLevel.Trace;
		case 'debug':
			return LogLevel.Debug;
		case 'info':
			return LogLevel.Info;
		case 'warn':
			return LogLevel.Warning;
		case 'error':
			return LogLevel.Error;
		case 'critical':
			return LogLevel.Error;
		case 'off':
			return LogLevel.Off;
	}
	return undefined;
}