Objective of issue: Refactor builder into module builders

Lava version:

• 0.3.0 (feature release)

I'm submitting a ...

• code refactor

Current behavior:

• builder.py is currently part of the src/lava/magma/compiler/ module

Expected behavior:

• builder.py should be refactored, creating abstract interfactes.py and both should be moved to module src/lava/magma/compiler/builders module