Splits of modules into smaller files

[Hecatron]

I suspect this probably won't go through as is.
But what I've done here is split the modules up into sub-directories with smaller files inside on a mostly struct boundary.
The module namespace should be the same as before so all the tests and examples still work fine.

What I'm aiming for is designing my own cli that can be used on an embedded device or desktop terminal.
Something similar to the serial interfaces on cisco or fortigate devices where you can auto complete or get hints / options by hitting tab
The source files are a bit on the big side though for me to work out where everything is located.

Since I'm a bit new to rust coming from other languages
I'm not sure if separating things out this way is a proper rust way of doing things, or if it's just a question of code style
but I figured I'd see about getting some feedback to see if this is a good or bad idea.