Move pylibcudf/libcudf/wrappers/decimals to pylibcudf/libcudf/fixed_p…

…oint (#17048)

Contributes to #15162

I don't think there are any types in this file that needs to be exposed on the Python side; they're just used internally in pylibcudf.

Also moves this to `libcudf/fixed_point` matching the libcudf location more closely

Authors:
  - Matthew Roeschke (https://github.com/mroeschke)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #17048

python/pylibcudf/pylibcudf/libcudf/fixed_point/fixed_point.pxd

@@ -0,0 +1,8 @@
+# Copyright (c) 2021-2024, NVIDIA CORPORATION.
+
+from libc.stdint cimport int32_t
+
+
+cdef extern from "cudf/fixed_point/fixed_point.hpp" namespace "numeric" nogil:
+    cdef cppclass scale_type:
+        scale_type(int32_t)

python/pylibcudf/pylibcudf/libcudf/scalar/scalar.pxd

@@ -4,9 +4,9 @@ from libc.stdint cimport int32_t, int64_t
 from libcpp cimport bool
 from libcpp.string cimport string
 from pylibcudf.libcudf.column.column_view cimport column_view
+from pylibcudf.libcudf.fixed_point.fixed_point cimport scale_type
 from pylibcudf.libcudf.table.table_view cimport table_view
 from pylibcudf.libcudf.types cimport data_type
-from pylibcudf.libcudf.wrappers.decimals cimport scale_type
 
 
 cdef extern from "cudf/scalar/scalar.hpp" namespace "cudf" nogil: