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.

TactilityKernel/source/drivers/gpio_backlight.cpp

@@ -125,7 +125,7 @@ static error_t stop(Device* device) {
 
 // endregion
 
-extern Module root_module;
+extern Module kernel_module;
 
 Driver gpio_backlight_driver = {
     .name = "gpio_backlight",
@@ -134,7 +134,7 @@ Driver gpio_backlight_driver = {
     .stop_device = stop,
     .api = &GPIO_BACKLIGHT_API,
     .device_type = &BACKLIGHT_TYPE,
-    .owner = &root_module,
+    .owner = &kernel_module,
     .internal = nullptr
 };