Qt6 & Qt5 version

[RaymiiOrg]

This build incorporates fixes from MenloSystems ( @olafmandel ) and compiles under Qt5.15 and Qt6.5 (without warnings). A GitHub Actions file is included to build under Qt5 an Qt6.

I havent ran the tests yet but that could be incorporated into the GitHub actions runner. The project seems dead so i'm unsure of that is worth the effort.

[srijanc]

@RaymiiOrg I have been using these changes for an ongoing project that I am working on. I came across a well known warning QRegularExpressionPrivate::doMatch(): called on an invalid QRegularExpression object which occurs if the RegExpFilter property pattern contains a special character which has a meaning within a regular expression, in my case ( or ) or [ or ] . The warning is thrown in multiple times and then it stops and the list model fails to produce correct result

• Here is a sample code of my RegExpFilter:

              RegExpFilter {
                  roleName: "firstName"
                  pattern: "Aaron Stevens - 123132542 ("
                  caseSensitivity: Qt.CaseInsensitive
              }

  May I know if I am missing something in my implementation or do I need to filter my text from these special characters? Just to confirm, no such warnings were observed when using the released version of SortFilterProxyModel