The CppSuite represents a large chunk of WT stress testing and is currently not running on ARM64. We should add a new variant to our evergreen.yml to run the CppSuite stress tests.

Scope:

• Add a new variant to the evergreen.yml, copying over the tasks from CppSuite stress tests
• Rename the original variant to CppSuite Stress Tests Ubuntu 20.04
• Check that all tests are passing