Added Dispatcher and fix sim (#54)

- Add dispatcher mechanism (a queue for function calls) and tests
- Added tests for MessageQueue
- Fix FreeRTOS config for simulator
- Explicit dependencies for touch-related libs, because minor version changes caused broken builds on CI.

tests/tactility-core/dispatcher_test.cpp

@@ -0,0 +1,38 @@
+#include "doctest.h"
+#include "tactility_core.h"
+#include "dispatcher.h"
+
+void increment_callback(void* context) {
+    auto* counter = (uint32_t*)context;
+    (*counter)++;
+}
+
+TEST_CASE("dispatcher should not call callback if consume isn't called") {
+    Dispatcher* dispatcher = tt_dispatcher_alloc(10);
+
+    uint32_t counter = 0;
+    tt_dispatcher_dispatch(dispatcher, &increment_callback, &counter);
+    tt_delay_tick(10);
+    CHECK_EQ(counter, 0);
+
+    tt_dispatcher_free(dispatcher);
+}
+
+
+TEST_CASE("dispatcher should be able to dealloc when message is not consumed") {
+    Dispatcher* dispatcher = tt_dispatcher_alloc(10);
+    uint32_t counter = 0;
+    tt_dispatcher_dispatch(dispatcher, increment_callback, &counter);
+    tt_dispatcher_free(dispatcher);
+}
+
+TEST_CASE("dispatcher should call callback when consume is called") {
+    Dispatcher* dispatcher = tt_dispatcher_alloc(10);
+
+    uint32_t counter = 0;
+    tt_dispatcher_dispatch(dispatcher, increment_callback, &counter);
+    tt_dispatcher_consume(dispatcher, 100);
+    CHECK_EQ(counter, 1);
+
+    tt_dispatcher_free(dispatcher);
+}