#23 Fix "error: ‘string’ in namespace ‘std::__cxx11’ does not name a type" while building on Archlinux

../../editor/sinsyscoreconverter.cpp:38:59: error: ‘string’ in namespace ‘std::__cxx11’ does not name a type
   38 | bool SinsyScoreConverter::setEncoding(const std::__cxx11::string &encoding) {
      |                                                           ^~~~~~
../../editor/sinsyscoreconverter.cpp:38:6: error: no declaration matches ‘bool SinsyScoreConverter::setEncoding(const int&)’
   38 | bool SinsyScoreConverter::setEncoding(const std::__cxx11::string &encoding) {
      |      ^~~~~~~~~~~~~~~~~~~
[...]
../../editor/sinsyscoreconverter.cpp: At global scope:
../../editor/sinsyscoreconverter.cpp:119:42: error: ‘string’ in namespace ‘std::__cxx11’ does not name a type
  119 |     size_t duration, const std::__cxx11::string &lyric, size_t pitch,
      |                                          ^~~~~~
../../editor/sinsyscoreconverter.cpp:118:6: error: no declaration matches ‘bool SinsyScoreConverter::addNote(size_t, const int&, size_t, bool, bool, sinsy::TieType, sinsy::SlurType, sinsy::SyllabicType, bool)’
  118 | bool SinsyScoreConverter::addNote(
      |      ^~~~~~~~~~~~~~~~~~~

Trying to build on Archlinux but it fails with: ``` ../../editor/sinsyscoreconverter.cpp:38:59: error: ‘string’ in namespace ‘std::__cxx11’ does not name a type 38 | bool SinsyScoreConverter::setEncoding(const std::__cxx11::string &encoding) { | ^~~~~~ ../../editor/sinsyscoreconverter.cpp:38:6: error: no declaration matches ‘bool SinsyScoreConverter::setEncoding(const int&)’ 38 | bool SinsyScoreConverter::setEncoding(const std::__cxx11::string &encoding) { | ^~~~~~~~~~~~~~~~~~~ [...] ../../editor/sinsyscoreconverter.cpp: At global scope: ../../editor/sinsyscoreconverter.cpp:119:42: error: ‘string’ in namespace ‘std::__cxx11’ does not name a type 119 | size_t duration, const std::__cxx11::string &lyric, size_t pitch, | ^~~~~~ ../../editor/sinsyscoreconverter.cpp:118:6: error: no declaration matches ‘bool SinsyScoreConverter::addNote(size_t, const int&, size_t, bool, bool, sinsy::TieType, sinsy::SlurType, sinsy::SyllabicType, bool)’ 118 | bool SinsyScoreConverter::addNote( | ^~~~~~~~~~~~~~~~~~~ ``` Simply removing "__cxx11::", leaving it as "std::string", fixes it.