Simplified regex split

Instead of building the result vector with push_back, I now use
the vector c'tor with iterators directly.

src/string_utils.cpp

@@ -32,12 +32,7 @@ vector<string> sc::split(const string& str, const string& sep)
 }
 
 vector<string> sc::split(const string& str, const regex& sep) {
-    vector<string> components;
-    sregex_token_iterator end {};
-    for (sregex_token_iterator p {str.begin(), str.end(), sep, -1}; p != end; ++p) {
-        components.push_back(*p);
-    }
-    return components;
+    return {sregex_token_iterator {str.begin(), str.end(), sep, -1}, sregex_token_iterator {}};
 }
 
 string sc::join(const vector<string>& components, const string& join)