Add a way to influence the CMake kit name for qt-core.additionalPaths

Image, you have multiple Qt builds of the same version, e.g. a shared and a static build. Then we currently generate something like this:

  {
    "name": "Qt-6.9.0-linux-clang",
...
    "toolchainFile": "/home/jobor/dev/qt/dev-native/qtbase/lib/cmake/Qt6/qt.toolchain.cmake",
...
  },
  {
    "name": "Qt-6.9.0-linux-clang",
...
    "toolchainFile": "/home/jobor/dev/qt/dev-static/qtbase/lib/cmake/Qt6/qt.toolchain.cmake",
...
  },

Both kits have the same name. After running "CMake: Scan for Kits" the second kit is removed.

We need to make sure to generate unique kit names. A very simple solution is to add a number at the end.

A user will want to have some say in how the kit is named though. One idea is to allow objects in qt-core.additionalPathNames. Something like

   "qt-core.additionalQtPaths": [
        "/home/egon/dev/qt/dev-native/qtbase/bin/qmake",
        {
           path:  "/home/egon/dev/qt/dev-static/qtbase/bin/qmake",
           name: "Qt-dev-static"
         }
    ]

The above would create two kits: "Qt-6.9.0-linux-g++" and "Qt-dev-static".