changed the directory structure of the generated entity files

[kev1N916]

PR Info

Closes #2690

New Features

Changes the directory structure of the generated entitity files.

output-dir/
    entities.rs
    entities/
            foo.rs
            bar.rs
            prelude.rs

[Huliiiiii]

I think we should add a new flag and set the previous one as the default value.

[kev1N916]

@Huliiiiii I've added a new flag.
If it is set the new structure will be followed else the old structure will be followed

[Huliiiiii]

Some alternatives:

• (use_)new_module_(style/structure/layout): bool
• module_(style/structure/layout): (old, 2018)

@tyt2y3 What do you think?

[tyt2y3]

I think this is a good idea, although we need to provide a flag for compatiblity and fix the conflicts.