refactor: introduce single-separator split helper SplitString

This helper uses spanparsing::Split internally and enables to replace
all calls to boost::split where only a single separator is passed.

Co-authored-by: Martin Ankerl <Martin.Ankerl@gmail.com>
Co-authored-by: MarcoFalke <falke.marco@gmail.com>

src/util/string.h

@@ -6,6 +6,7 @@
 #define BITCOIN_UTIL_STRING_H
 
 #include <attributes.h>
+#include <util/spanparsing.h>
 
 #include <algorithm>
 #include <array>
@@ -15,6 +16,11 @@
 #include <string>
 #include <vector>
 
+[[nodiscard]] inline std::vector<std::string> SplitString(std::string_view str, char sep)
+{
+    return spanparsing::Split<std::string>(str, sep);
+}
+
 [[nodiscard]] inline std::string TrimString(const std::string& str, const std::string& pattern = " \f\n\r\t\v")
 {
     std::string::size_type front = str.find_first_not_of(pattern);