refs #9178
- `checkFileExists` and `checkFileIsValid` where dirty required from web/middleware
- these two functions are only used in the target middleware
- let's move them
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
refs #9178
- we have to take care that we don't end up in circular dependencies
- e.g. API requires UrlService and UrlService needs to require the API (for requesting data)
- update the references
- we would like to get rid of the utils folder, this is/was the most complicated change
refs #9178
- move express apps to one place (called `web`)
- requires https://github.com/TryGhost/Ghost-Admin/pull/923
- any further improvements are not part of this PR
- this PR just moves the files and ensures the paths are up-to-date
