Debugger: DAPEngine improve breakpoints handling

- Added proper "Insert" breakpoint
- Added proper "Remove" breakpoint
- Fixed errors with engine states after pause and continue

Change-Id: Icbe1b4cf549cee633809d0a1c9ab19dbf877dbf0
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/debugger/dap/dapengine.h

@@ -92,6 +92,7 @@ private:
 
     QByteArray m_inbuffer;
     Utils::QtcProcess m_proc;
+    int m_nextBreakpointId = 1;
 };
 
 } // Debugger::Internal