Testsuite: fix breakage

- visible Signature of TestFrame changed due to being relocated into the Vault

- attempt to make the WorkForce_test more robust;
  frequently fails on testsuite run after full build;
  so better ''wait'' for the workers to have started working,
  instead of using a fixed delay (that must be extremely short
  and is hard to predict)

tests/steam/engine/node-devel-test.cpp

@@ -296,7 +296,7 @@ namespace test  {
           // generate a binding as processing-functor
           auto procFun = spec.makeFun();
           using Sig = lib::meta::_Fun<decltype(procFun)>::Sig;
-          CHECK (showType<Sig>() == "void (tuple<ulong, uint>, engine::TestFrame*)"_expect);
+          CHECK (showType<Sig>() == "void (tuple<ulong, uint>, TestFrame*)"_expect);
 
           // Behaves identical to processing_generateFrame() — see above...
           size_t frameNr = defaultGen.u64();

tests/vault/gear/work-force-test.cpp

@@ -322,9 +322,8 @@ namespace test {
           wof.incScale();
           wof.incScale();
           
-          sleep_for(10us);
+          while (not check) /*spin*/;
           CHECK (3 == wof.size());
-          CHECK (0  < check);
           CHECK (0 == errors);
           
           sleep_for(200ms);   // wait for the programmed disaster