[TIR][Schedule]Generalize fuseReductionEpilogue to support arbitrary epilogue expressions (#18636)

## Major Changes for Generalization

### 1. Pattern Matching Removal

**Removed Items:**
- `EpilogueType` enum (Bias, BiasReLU, Clipping)
- `AnalyzeEpiloguePattern()` function
- Pattern-specific branching logic

**Current Approach:**
- Directly process the entire epilogue expression without pattern
matching

### 2. Store Entire Epilogue Expression

- Store the entire epilogue expression in `epilogue_expression_`
- Use the expression directly without pattern analysis

```cpp
// Store the epilogue expression and reduction buffer load
epilogue_expression_ = inlined_store_->value;
reduction_buffer_load_ = loads[0];
```
### 3. Generalized Init Transformation

- Replace reduction buffer load with identity element (0)
- Apply to the entire expression to generate init value

```cpp
InitSubstituter init_subst(inlined_buffer_, identity_elem);
PrimExpr init_epilogue = init_subst(epilogue_expression_);
// Simplify: 0 + C[vi, vj] -> C[vi, vj]
```

**Examples:**
- `temp + C` → `0 + C` → `C` (simplify)
- `max(temp + C, 0)` → `max(0 + C, 0)` → `max(C, 0)`
- `min(max(temp, lower), upper)` → `min(max(0, lower), upper)`

### 4. Generalized Update Transformation

- Replace reduction buffer load with reduction update
- If parent is Add and the other operand is not a reduction buffer →
treat as bias addend and remove
- Otherwise → apply expression as-is

```cpp
class GeneralizedEpilogueApplier : public ExprMutator {
  // Replace reduction buffer load with reduction update
  // Automatically detect and remove bias addend in Add nodes
  // Automatically support other activation functions
};
```

## Results and Verification

### Existing Tests Pass

All existing tests pass, maintaining backward compatibility:

- `test_fuse_reduction_epilogue_basic` 
- `test_fuse_reduction_epilogue_fp32` 
- `test_fuse_reduction_epilogue_numerical_correctness` 
- `test_fuse_reduction_epilogue_multiple_epilogue` 
- `test_matmul_bias_relu` 
- `test_matmul_bias_relu_correctness_unified` 
- `test_matmul_clipping` 
- `test_matmul_clipping_correctness_unified` 
- Other commutative variants tests 

Total: All 15 tests pass

---------

Signed-off-by: Hyun Gyu Kim <kimm240@telepix.net>
Co-authored-by: Hyun Gyu Kim <kimm240@telepix.net>

Author: kimm240