when user passes undefined to our unary methods, we throw an error due to trace logging

[bruuuuuuuce]

This happens when using pure javascript

        this.logger.trace(`Issuing 'get' request; key: ${key.toString()}`);
                                                             ^

TypeError: Cannot read properties of undefined (reading 'toString')

Should return an instance of CacheGet.Error

Validation would go around here https://github.com/momentohq/client-sdk-javascript/blob/main/packages/client-sdk-nodejs/src/internal/cache-data-client.ts#L291-L295