schema2kotlin: Generation of Empty entities + added imports (#3897)
schema2kotlin: Generation of Empty entities + added imports (#3897)

* fixed a few kotlin issues
- Now importing classes from arcs package given custom package
- On generation of classes with no fields, generate class, not data class.

* using correct kotlin indentation

* rm unnecessary imports

* fix: imports
fix: imports
- alphabetic import order
- no `;`

* Revert "using correct kotlin indentation"

This reverts commit 0f146e4b

* ++idiomatic kotlin

PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs