Does any one of you know a solution to either read or edit on an iPad files stored with Textedit on iCloud ?
As @patrix said there is no way.
However you can use iA Writer. It's an application available for Mac, iPad and iPhone, which allows you to read and write
Unfortunately it is not free.
Alternatively Brett Terpstra has an amazingly comprehensive review of iOS editors where you can find a replacement or be alerted when a program does in fact cooperate with TextEdit for document storage in iCloud.