Move tests to relevant subprojects (#615)

- Moved test projects to the parent project they belong to
- Improved test stability/corectness
- Improved recursive directory deletion by safely ignoring current- and parent-directory entries.
- Update docs

TactilityFreeRtos/Tests/Source/DispatcherThreadTest.cpp

@@ -0,0 +1,32 @@
+#include "doctest.h"
+#include <Tactility/DispatcherThread.h>
+#include <Tactility/Semaphore.h>
+
+using namespace tt;
+
+TEST_CASE("DispatcherThread state test") {
+    DispatcherThread thread("test");
+    CHECK_EQ(thread.isStarted(), false);
+
+    thread.start();
+    CHECK_EQ(thread.isStarted(), true);
+
+    thread.stop();
+    CHECK_EQ(thread.isStarted(), false);
+}
+
+TEST_CASE("DispatcherThread should consume jobs") {
+    DispatcherThread thread("test");
+    thread.start();
+    int counter = 0;
+    Semaphore done(1, 0);
+
+    thread.dispatch([&counter, &done]() {
+        counter++;
+        done.release();
+    });
+
+    CHECK(done.acquire(pdMS_TO_TICKS(2000)));
+    CHECK_EQ(counter, 1);
+    thread.stop();
+}