Remove TactilityC and Firmware subprojects (#638)

- Removed TactilityC, moved its symbols to existing modules and several new ones (pthread-module, c-symbols-module, cpp-symbols-module, posix-symbols-module, freertos-module).
- Removed Firmware subproject and moved main() into Tactility subproject.
- Strengthened application archive, path, version, stack-size, and device validation.
- Moved symbol resolution for elf_loader to app-esp32-module.
- Improved `struct Module` declarations and made module and symbol definitions in modules more consistent.
- Removed old http download code from Tactility subproject.
- Rename app-module's source files for consistency.
- Add missing pthread symbols.
- Kernel module symbols are now resolvable on all platforms.

Modules/app-esp32-module/source/module.cpp

@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: Apache-2.0
 #include <app_esp32/module.h>
 
+#include <private/elf_symbol.h>
+
 #include <service/manager.h>
 
 #include <tactility/error.h>
@@ -10,11 +12,23 @@ extern "C" {
 
 extern ServiceManifest loader_service_manifest;
 
+// Overrides elf_loader's default KConfig-based symbol resolver with one that looks up symbols
+// across every started kernel module's own symbol table instead.
+uintptr_t app_esp32_symbol_resolver(const char* symbolName) {
+    uintptr_t symbol_address;
+    if (module_resolve_symbol_global(symbolName, &symbol_address)) {
+        return symbol_address;
+    }
+    return 0;
+}
+
 static error_t start() {
+    elf_set_symbol_resolver(app_esp32_symbol_resolver);
     return service_manager_add(&loader_service_manifest, /*auto_start=*/true);
 }
 
 static error_t stop() {
+    elf_set_symbol_resolver(nullptr);
     return service_manager_remove(loader_service_manifest.id);
 }
 
@@ -24,7 +38,7 @@ Module app_esp32_module = {
     .stop = stop,
     .drivers = nullptr,
     .symbols = nullptr,
-    .internal = nullptr
+    .internal = nullptr,
 };
 
 }