CMake update for engine, gui, launcher, mdserver, and viewer libs

[biagas]

Description

Update CMake logic to utilize visit_add_library, visit_add_parallel_library.

Updated FindQWT to create exportable import targets.

Type of change

• [ ] Bug fix
• [ ] New feature
• [ ] Documentation update
• [X] Other CMake modernization effort.

How Has This Been Tested?

Compiled and packaged/installed successfully on Windows, Linux.

Checklist:

• [X] I have commented my code where applicable.~~
• [ ] I have updated the release notes.
• [ ] I have made corresponding changes to the documentation.
• [ ] I have added debugging support to my changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [ ] I have confirmed new and existing unit tests pass locally with my changes.
• [ ] I have added new baselines for any new tests to the repo.
• [ ] I have NOT made any changes to [protocol or public interfaces][3] in an RC branch.