[geary] (7 commits) ...Merge branch 'mjog/async-unit-test-improvements' into 'mainline'

[Michael Gratton <mjog src gnome org>]

Summary of changes:

  02adcfa... test/mock-object.vala: Allow ExpectedCall to specify async  (*)
  749096c... test/mock-object.vala: Add explicit support for mocking asy (*)
  768f6af... test/test-case.vala: Add AsyncResultWaiter class (*)
  196f05e... test/test-case.vala: Rename TestCase async calls to match A (*)
  c98efaf... Fix failing test after test case async changes (*)
  d84899e... test: Enable engine logging if test harness verbose flag is (*)
  ef68f3c... Merge branch 'mjog/async-unit-test-improvements' into 'main

(*) This commit already existed in another branch; no separate mail sent