* Qt6: Avoid insertWidget, use addWidget
In Qt6, the insertWidget function checks if the index parameter is valid based on current widgets present in the layout. This is error prone, and use addWidget to avoid manual counting of index.
* Disable use of Qt keyword foreach
* Replace use of QRegExp with QRegularExpression
Replace use of QRegExp with QRegularExpression
Remove dependency on qt5compat module
Simplify an expression based on review
* Remove Qt5 ifdefs
* Guard access out of bounds seen in debug build
* Avoid reuse of string variable
* Disconnect all signals from the QOpenGLContext
The call stack when this assert happens indicates that there are more signals to be disconnected from the object. Crash is fixed by disconnecting all signals.
Assert seen in debug build:
ASSERT failure in caf::Viewer: "Called object is not of the correct type (class destructor may have already run)", file C:\Qt\6.6.3\msvc2019_64\include\QtCore/qobjectdefs_impl.h, line 130
* Fix issue related to delete of a linked view
Guard null pointer use in view linker. Remove complicated cleanup in destructor in Rim3dVew.
