feat: add very early mod.toml packwiz support

Also use it as a on-disk format for storing mod metadata. This will be
used later on to make better mod managment.

launcher/modplatform/ModIndex.h

@@ -8,6 +8,35 @@
 
 namespace ModPlatform {
 
+enum class Provider{
+    MODRINTH,
+    FLAME
+};
+
+class ProviderCapabilities {
+   public:
+    static QString hashType(Provider p) 
+    {
+        switch(p){
+        case Provider::MODRINTH:
+            return "sha256";
+        case Provider::FLAME:
+            return "murmur2";
+        }
+        return "";
+    }
+    static QString providerName(Provider p) 
+    {
+        switch(p){
+        case Provider::MODRINTH:
+            return "modrinth";
+        case Provider::FLAME:
+            return "curseforge";
+        }
+        return "";
+    }
+};
+
 struct ModpackAuthor {
     QString name;
     QString url;
@@ -26,6 +55,7 @@ struct IndexedVersion {
 
 struct IndexedPack {
     QVariant addonId;
+    Provider provider;
     QString name;
     QString description;
     QList<ModpackAuthor> authors;
@@ -40,3 +70,4 @@ struct IndexedPack {
 }  // namespace ModPlatform
 
 Q_DECLARE_METATYPE(ModPlatform::IndexedPack)
+Q_DECLARE_METATYPE(ModPlatform::Provider)