Add explicit version information to required packages for CMake

[trisyoungs]

Describe the bug
Having just tried to compile Dissolve on my laptop (OpenSuSE 15.4, Qt6 6.2) I discovered that the new usage of qt_generate_deploy_qml_app_script depends on Qt6 >=6.7.

Our current find_package calls do not have any version requirements set throughout, so we should add these.

• Qt >= 6.7
• ANTLR4 (Java) >= 4
• ANTLR runtime >= 4.11

[trisyoungs]

Building against Qt 6.7 on my machines (OpenSuSE) appears to be broken...

During configuration:

CMake Warning at /usr/lib64/cmake/Qt6Qml/Qt6QmlMacros.cmake:3393 (message):
  The qml plugin 'qquicklayoutsplugin' is a dependency of 'dissolve-gui', but
  the link target it defines (Qt6::qquicklayoutsplugin) does not exist in the
  current scope.  The plugin will not be linked.
Call Stack (most recent call first):
  /usr/lib64/cmake/Qt6Core/Qt6CoreMacros.cmake:678 (qt6_import_qml_plugins)
  /usr/lib64/cmake/Qt6Core/Qt6CoreMacros.cmake:678 (cmake_language)
  /usr/lib64/cmake/Qt6Core/Qt6CoreMacros.cmake:774 (_qt_internal_finalize_executable)
  /usr/lib64/cmake/Qt6Core/Qt6CoreMacros.cmake:590:EVAL:1 (qt6_finalize_target)
  CMakeLists.txt:DEFERRED

... and many other plugin libraries related to qml.

And during compilation:

/home/tris/src/dissolve/build-release/src/gui/models/moc_sortFilterProxy.cpp:131:69: error: static assertion failed: NOTIFY signal read does not exist in class (or is private in its parent)
  131 | static_assert(qxp::is_detected_v<has_nullary_read, SortFilterProxy> || qxp::is_detected_v<has_unary_read, SortFilterProxy>,

[trisyoungs]

But it seems building against 6.6.3 works just fine without errors. So, errr, maybe ignore all of this.