Add initial stress test (#2364)

We need to make a test that runs longer than the tests we had before to check
some problems that might happen after running for some time (e.g. memory
corruption or something else).

core/iwasm/libraries/lib-wasi-threads/test/skip.json

@@ -0,0 +1,5 @@
+{
+    "lib-wasi-threads tests": {
+        "spawn_stress_test": "Stress tests are incompatible with the other part and executed differently"
+    }
+}