Add functional tests for test adapter#21803

eleanorjboyd merged 12 commits intomicrosoft:feature-branch-testing-overflow-bug-fixmicrosoft/vscode-python:feature-branch-testing-overflow-bug-fixfrom

eleanorjboyd:functional-tests-for-testingeleanorjboyd/vscode-python:functional-tests-for-testingCopy head branch name to clipboard