`A15-1-3`: Detection of duplicated exceptions on function templates

### Affected rules
 - A15-1-3

### Description

When defining a function template which throws an exception, `A15-1-3` warning is triggered, meaning that the exception is not unique.

### Example
```cpp
template <typename T>
void false_positive() {
  throw std::runtime_error{"message"}; // Triggers A15-1-3 warning
}
```
