ARROW-9991: [C++] Split kernels for strings/binary

Contains:
 * `split_pattern` kernel with max_split and reverse option
 * `ascii_split_whitespace` similar to Python's `bytes.split`
 * `utf8_split_whitespace` similar to Python's `str.split`

It should be easy to add new split methods, e.g. a regex one in the future.

Closes #8271 from maartenbreddels/ARROW-9991

Authored-by: Maarten A. Breddels <maartenbreddels@gmail.com>
Signed-off-by: Antoine Pitrou <antoine@python.org>

Author: maartenbreddels

cpp/src/arrow/compute/api_scalar.h

@@ -49,6 +49,25 @@ struct ARROW_EXPORT MatchSubstringOptions : public FunctionOptions {
   std::string pattern;
 };
 
+struct ARROW_EXPORT SplitOptions : public FunctionOptions {
+  explicit SplitOptions(int64_t max_splits = -1, bool reverse = false)
+      : max_splits(max_splits), reverse(reverse) {}
+
+  /// Maximum number of splits allowed, or unlimited when -1
+  int64_t max_splits;
+  /// Start splitting from the end of the string (only relevant when max_splits != -1)
+  bool reverse;
+};
+
+struct ARROW_EXPORT SplitPatternOptions : public SplitOptions {
+  explicit SplitPatternOptions(std::string pattern, int64_t max_splits = -1,
+                               bool reverse = false)
+      : SplitOptions(max_splits, reverse), pattern(std::move(pattern)) {}
+
+  /// The exact substring to look for inside input values.
+  std::string pattern;
+};
+
 /// Options for IsIn and IndexIn functions
 struct ARROW_EXPORT SetLookupOptions : public FunctionOptions {
   explicit SetLookupOptions(Datum value_set, bool skip_nulls)