Update to Qt5.15 and Qt6

[kassane]

closes #3

Preview - config

Qt5.15.x

-- The C compiler identification is GNU 13.2.1
-- The CXX compiler identification is GNU 13.2.1
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Initializing..
-- os_version_suffix:n/a
Add flag to compile for Ubuntu 16 and above
-- Performing system check..
-- Identifing bitness of the platform..
-- Bitness of the platform: 64
-- Performing system check - done
-- Adding perl scripts to build..
--  PROJECT_INCLUDE_DIR: /home/kassane/ldQt/ldmicro/includes
-- The following REQUIRED packages have been found:

 * QT
 * Qt5Core (required version >= 5.15.11)
 * Qt5Gui (required version >= 5.15.11)
 * Qt5Widgets
 * Qt5

-- Configuring done (0.3s)
-- Generating done (0.0s)
-- Build files have been written to: /home/kassane/LDmicroQt/build

Qt6.6.x

-- The C compiler identification is GNU 13.2.1
-- The CXX compiler identification is GNU 13.2.1
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Initializing..
-- os_version_suffix:n/a
Add flag to compile for Ubuntu 16 and above
-- Performing system check..
-- Identifing bitness of the platform..
-- Bitness of the platform: 64
-- Performing system check - done
-- Adding perl scripts to build..
--  PROJECT_INCLUDE_DIR: /home/kassane/ldQt/ldmicro/includes
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Performing Test HAVE_STDATOMIC
-- Performing Test HAVE_STDATOMIC - Success
-- Found WrapAtomic: TRUE  
-- Found OpenGL: /usr/lib/libOpenGL.so   
-- Found WrapOpenGL: TRUE  
-- Found XKB: /usr/lib/libxkbcommon.so (found suitable version "1.6.0", minimum required is "0.5.0") 
-- Found WrapVulkanHeaders: /usr/include  
-- The following OPTIONAL packages have been found:

 * Qt6WidgetsTools (required version >= 6.6.0)
 * Qt6CoreTools (required version >= 6.6.0)
 * OpenGL
 * PkgConfig
 * XKB (required version >= 0.5.0), XKB API common to servers and clients., <http://xkbcommon.org>
 * Vulkan
 * WrapVulkanHeaders
 * Qt6GuiTools (required version >= 6.6.0)
 * Qt6DBusTools (required version >= 6.6.0)
 * Qt6Widgets

-- The following REQUIRED packages have been found:

 * QT
 * Qt6

-- Configuring done (0.6s)
-- Generating done (0.0s)
-- Build files have been written to: /home/kassane/LDmicroQt/build

cc: @akshay-c