chore(Probability): split Independence.Kernel (#32327)

Create a new folder `Kernel` with two files: `Indep` is about independence of families of sets and sigma-algebras, while `IndepFun` contains the definitions and results about independence of random variables.

Author: EtienneC30

Mathlib.lean

@@ -5633,7 +5633,8 @@ public import Mathlib.Probability.Independence.Conditional
 public import Mathlib.Probability.Independence.InfinitePi
 public import Mathlib.Probability.Independence.Integrable
 public import Mathlib.Probability.Independence.Integration
-public import Mathlib.Probability.Independence.Kernel
+public import Mathlib.Probability.Independence.Kernel.Indep
+public import Mathlib.Probability.Independence.Kernel.IndepFun
 public import Mathlib.Probability.Independence.Process
 public import Mathlib.Probability.Independence.ZeroOne
 public import Mathlib.Probability.Integration

Mathlib/Probability/Independence/Basic.lean

@@ -5,7 +5,7 @@ Authors: Rémy Degenne
 -/
 module
 
-public import Mathlib.Probability.Independence.Kernel
+public import Mathlib.Probability.Independence.Kernel.IndepFun
 public import Mathlib.MeasureTheory.Constructions.Pi
 public import Mathlib.MeasureTheory.Group.Convolution
 

Mathlib/Probability/Independence/Conditional.lean

@@ -5,7 +5,7 @@ Authors: Rémy Degenne
 -/
 module
 
-public import Mathlib.Probability.Independence.Kernel
+public import Mathlib.Probability.Independence.Kernel.IndepFun
 public import Mathlib.Probability.Kernel.CompProdEqIff
 public import Mathlib.Probability.Kernel.Composition.Lemmas
 public import Mathlib.Probability.Kernel.Condexp