Make new tab name translatable

Fix #2837

PowerEditor/installer/nativeLang/english.xml

@@ -1416,6 +1416,7 @@ Find in all files except exe, obj && log:
             <find-result-line-prefix value="Line"/> <!-- Must not begin with space or tab character -->
             <find-regex-zero-length-match value="zero length match" />
             <session-save-folder-as-workspace value="Save Folder as Workspace" />
+            <tab-untitled-string value="new " />
         </MiscStrings>
     </Native-Langue>
 </NotepadPlus>

PowerEditor/installer/nativeLang/french.xml

@@ -1358,6 +1358,7 @@ Rechercher dans tous les fichiers sauf exe, obj && log:
             <find-result-line-prefix value="Ligne"/> <!-- Must not begin with space or tab character -->
             <find-regex-zero-length-match value="la chaîne vide trouvée" />
             <session-save-folder-as-workspace value="&quot;Dossier en tant qu'espace de travail&quot; inclus" />
+            <tab-untitled-string value="nouveau " />
         </MiscStrings>
     </Native-Langue>
 </NotepadPlus>

PowerEditor/installer/nativeLang/taiwaneseMandarin.xml

@@ -1342,6 +1342,7 @@
             <find-result-line-prefix value="行號"/> <!-- Must not begin with space or tab character -->
             <find-regex-zero-length-match value="零長度的字元相符" />
             <session-save-folder-as-workspace value="包含「資料夾工作區」" />
+            <tab-untitled-string value="新文件 " />
         </MiscStrings>
     </Native-Langue>
 </NotepadPlus>

PowerEditor/src/ScintillaComponent/Buffer.cpp

@@ -497,6 +497,9 @@ void FileManager::init(Notepad_plus * pNotepadPlus, ScintillaEditView * pscratch
 	_pscratchTilla->execute(SCI_SETUNDOCOLLECTION, false);	//dont store any undo information
 	_scratchDocDefault = (Document)_pscratchTilla->execute(SCI_GETDOCPOINTER);
 	_pscratchTilla->execute(SCI_ADDREFDOCUMENT, 0, _scratchDocDefault);
+
+	NativeLangSpeaker *pNativeSpeaker = (NppParameters::getInstance()).getNativeLangSpeaker();
+	_untitled_str = pNativeSpeaker->getLocalizedStrFromID("tab-untitled-string", UNTITLED_STR);
 }
 
 void FileManager::checkFilesystemChanges(bool bCheckOnlyCurrentBuffer)

PowerEditor/src/ScintillaComponent/Buffer.h

@@ -58,6 +58,8 @@ enum SavingStatus
 	SaveWrittingFailed = 2
 };
 
+const TCHAR UNTITLED_STR[] = TEXT("new ");
+
 //File manager class maintains all buffers
 class FileManager final
 {
@@ -138,7 +140,7 @@ private:
 	std::vector<Buffer*> _buffers;
 	BufferID _nextBufferID = 0;
 	size_t _nbBufs = 0;
-	generic_string _untitled_str = TEXT("new ");
+	generic_string _untitled_str = UNTITLED_STR;
 };
 
 #define MainFileManager FileManager::getInstance()