[Core] Implement PatchModel and MasterModel classes

[tensquaresoftware]

Design and implement data model classes for managing Patch and Master parameter data.

Tasks:

• Define PatchModel class structure and responsibilities
• Define MasterModel class structure and responsibilities
• Determine relationship with APVTS (complement or replace?)
• Implement SysEx data conversion to/from models
• Add validation and boundary checking
• Implement serialization/deserialization
• Write unit tests for models

Questions to resolve:

• Should these models be redundant with APVTS or serve as a separate representation?
• How to keep models and APVTS synchronized?
• Should models be the single source of truth?

Context:
These models will represent the Matrix-1000's patch and master parameter data in a structured, type-safe way.