Move MiiData to its own namespace and add ChecksummedMiiData (#6824)

* Move mii to own namespace and add checksummed mii data

* Fix compile issues

* Make mii classes trivial and add cast operator

* Fix Android side

* Add new line at the end of files.

* Make miidata a struct and crc16 a u32_be as per switch code.

* Apply suggestions

* Change back crc to u16 and set padding to 0.

src/android/app/src/main/jni/applets/mii_selector.cpp

@@ -53,7 +53,7 @@ void AndroidMiiSelector::Setup(const Frontend::MiiSelectorConfig& config) {
     const u32 return_code = static_cast<u32>(
         env->GetLongField(data, env->GetFieldID(s_mii_selector_data_class, "return_code", "J")));
     if (return_code == 1) {
-        Finalize(return_code, HLE::Applets::MiiData{});
+        Finalize(return_code, Mii::MiiData{});
         return;
     }