closes#9022
Images without extensions don't need to be manipulated, as we're now reading the bytes and pass those to the `image-size` lib.
This PR adds another `user-agent` to emulate multiple browser requests, as I stumbled over an example where the image without extension is protected otherwise.
Added a test, that works with above mentioned image, but is currently mocked. Nevertheless, the image worked as a PoC, that we're able to read the bytes of an image without its extension and still return the dimensions of the image.
refs #9178
- i am not super happy about `const imageLib = require('../lib/image')`
- i don't really like the name `imageLib`
- but i had no better idea 😃
- if we use the same name in the whole project, it's very easy to rename the folder or the variable
