feat(sdk): add BasisParameterDriver for declarative animator parameter control

[towneh]

Summary

• Adds BasisParameterDriver, a StateMachineBehaviour that executes
  parameter operations (Set, Add, Random, Copy) on animator state entry.

• Adds BasisParameterDriverEditor, a custom inspector providing a
  card-based UI for managing operations with foldouts, reordering, and
  per-type field layouts.

Motivation

Currently there is no SDK-level way for creators to declaratively modify
animator parameters in response to state transitions. Creators either
need to write custom MonoBehaviours or rely on complex animator setups
to achieve common patterns like:

• Setting a parameter to a fixed value on state entry
• Accumulating a value over repeated transitions (Add)
• Randomising int/float/bool parameters with configurable ranges and
  repeat prevention
• Copying one parameter to another with optional range remapping

BasisParameterDriver covers all of these as a drop-in
StateMachineBehaviour.

What's included

File	Purpose
BasisParameterDriver.cs	Runtime behaviour — data model, execution logic, type-safe read/write helpers
BasisParameterDriverEditor.cs	Custom inspector — operation list UI with add/remove/reorder

Operation types

Type	Description
Set	Write a constant value to the destination parameter
Add	Read current value, add a delta, write back
Random	Roll a random float/int/bool with min/max, chance, and repeat prevention
Copy	Read from a source parameter and write to destination, with optional range remapping