Improve performance of dnp.nan_to_num (#2228)

This PR adds a dedicated kernel for `dnp.nan_to_num` to improve its
performance. This reduces the number of kernel calls to at most one in
all cases.

A kernel for both strided and contiguous inputs have been added, to
avoid additional allocation of device memory for trivial strides when
input is fully C- or F-contiguous.

For example of performance gains, using Max GPU

master:
```python
In [1]: import dpnp as dnp

In [2]: import numpy as np

In [3]: x_np = np.random.randn(10**9)

In [4]: x_np[np.random.choice(x_np.size, 200, replace=False)] = np.nan

In [5]: x = dnp.asarray(x_np)

In [6]: q = x.sycl_queue

In [7]: %time r = dnp.nan_to_num(x); q.wait()
CPU times: user 394 ms, sys: 43.8 ms, total: 438 ms
Wall time: 304 ms

In [8]: %time r = dnp.nan_to_num(x); q.wait()
CPU times: user 333 ms, sys: 31.8 ms, total: 364 ms
Wall time: 134 ms
```

on branch:
```python
In [8]: %time r = dnp.nan_to_num(x); q.wait()
CPU times: user 49.6 ms, sys: 8.1 ms, total: 57.7 ms
Wall time: 60.9 ms

In [9]: %time r = dnp.nan_to_num(x); q.wait()
CPU times: user 22.9 ms, sys: 16 ms, total: 38.9 ms
Wall time: 19.7 ms
```

Author: ndgrigorian

dpnp/backend/extensions/ufunc/CMakeLists.txt

@@ -38,6 +38,7 @@ set(_elementwise_sources
     ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/lcm.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/ldexp.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/logaddexp2.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/nan_to_num.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/radians.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/sinc.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/elementwise_functions/spacing.cpp

dpnp/backend/extensions/ufunc/elementwise_functions/common.cpp

@@ -38,6 +38,7 @@
 #include "lcm.hpp"
 #include "ldexp.hpp"
 #include "logaddexp2.hpp"
+#include "nan_to_num.hpp"
 #include "radians.hpp"
 #include "sinc.hpp"
 #include "spacing.hpp"
@@ -64,6 +65,7 @@ void init_elementwise_functions(py::module_ m)
     init_lcm(m);
     init_ldexp(m);
     init_logaddexp2(m);
+    init_nan_to_num(m);
     init_radians(m);
     init_sinc(m);
     init_spacing(m);