Better failure message when received object is undefined

[christian-bromann]

Given a simple scenario:

const elems = $$('div')
await expect(elems[123]).toHaveText('foobar')

This fails with Cannot read properties of undefined (reading 'getText') as the object passed into expect is undefined. We should provide a better error message here and fail early.

This should be also fixed in the @wdio/runner where we currently just pass in the browser if a passed in object is undefined.