Fix cmake builds on linux

[enaix]

There were some errors in cmakelists and linux wallpaper code that prevented it from compiling

[wangwenx190]

Thanks for your contribution!

[enaix]

I am currently trying to fix the issue with the qmlimportscanner: in demo/CMakeLists.txt

  qt_add_qml_module(Demo
      URI Demo
      VERSION 1.0
      IMPORTS
          QtQml
          QtQuick
          QtQuick.Controls.Basic
          org.wangwenx190.QtAcrylicMaterial
      QML_FILES MainWindow.qml
      IMPORT_PATH ${PROJECT_BINARY_DIR}/imports
      ENABLE_TYPE_COMPILER # <---
  ) 

qmlimportscanner reads ENABLE_TYPE_COMPILER as an import file. Might be an issue with indentation. QT Creator didn't print this warning for some reason, so I was confused and tried to fix a different issue.

Error copying file (if different) from "/home/fitz/src/smartwheel-core/opengl/qtacrylicmaterial/demo/ENABLE_TYPE_COMPILER" to "/home/fitz/src/smartwheel-core/opengl/qtacrylicmaterial/demo/Demo/ENABLE_TYPE_COMPILER".
CMake Warning at /usr/lib64/cmake/Qt6Qml/Qt6QmlMacros.cmake:1982 (message):
  Only .qml, .js or .mjs files should be added with QML_FILES.  The following
  files should be added with RESOURCES instead:

    ENABLE_TYPE_COMPILER
Call Stack (most recent call first):
  /usr/lib64/cmake/Qt6Qml/Qt6QmlMacros.cmake:575 (qt6_target_qml_sources)
  /usr/lib64/cmake/Qt6Qml/Qt6QmlMacros.cmake:626 (qt6_add_qml_module)
  demo/CMakeLists.txt:41 (qt_add_qml_module)

During the compilation, it throws qmlimportscanner: No such file or directory: "ENABLE_TYPE_COMPILER" error

[enaix]

I guess that I have found the source of an error: qt6-qtdeclarative-devel-6.3.1-2.fc36.x86_64 Fedora package provides /usr/lib64/cmake/Qt6Qml/Qt6QmlMacros.cmake, which has an error: it misses the ENABLE_TYPE_COMPILER option. In qtdeclarative source code Qt6QmlMacros.cmake the option is present.

EDIT: it is fixed in the most recent package version (rawhide branch)

[enaix]

Now the only remaining issue is that custom components are not found by the compiler in demo/MainWindow.qml: DesktopWallpaper was not found. Did you add all import paths?

Import statement does not throw any error, which is weird.