Reduce Evergreen Ubuntu build variant runtime by splitting up 'make check' tests

The current runtime of the Ubuntu build variant in Evergreen "WiredTiger" project is ~50 mins. Need to bring it down to ~15 mins, so that we can turn on the Evergreen Ubuntu tests as part of the pull request tests for wiredtiger/wiredtiger Git repository. 

The 2 most time consuming tasks in the Ubuntu build variant:

• compile (~49 mins) 
• unit-test (~21 mins)

Will use this ticket to split "make check" tests out of compile task into multiple new tasks, to reduce the overall runtime of Ubuntu build variant.