Allow in place modifications

[Baptouuuu]

Problem

When we want to modify a file and write it to the same path we are forced to create a temporary file and then read it to persist to the original path.

This exposes an implementation detail to the developer that should not be aware of such limitation.

Possible solution

When reading a Content from the filesystem we should keep attached this path to the instance so that when we try to persist the file we could detect if we're reading from the same path. In such case the abstraction should automatically use an temporary file to write to before moving it to the desired path.