major overhaul of Backend from dynamic to static dispatch using an big enum

crates/pacdef/src/backend/actual/fedora.rs

@@ -10,7 +10,19 @@ use crate::{Group, Package};
 
 #[derive(Debug, Clone)]
 pub struct Fedora {
-    pub(crate) packages: HashSet<Package>,
+    pub packages: HashSet<Package>,
+}
+impl Fedora {
+    pub fn new() -> Self {
+        Self {
+            packages: HashSet::new(),
+        }
+    }
+}
+impl Default for Fedora {
+    fn default() -> Self {
+        Self::new()
+    }
 }
 
 const BINARY: Text = "dnf";
@@ -123,14 +135,6 @@ impl Backend for Fedora {
     }
 }
 
-impl Fedora {
-    pub fn new() -> Self {
-        Self {
-            packages: HashSet::new(),
-        }
-    }
-}
-
 fn create_package(package: &str) -> Package {
     if DEFAULT_REPOS.iter().any(|repo| package.contains(repo)) && !package.contains("copr") {
         let package = package.split('/').nth(1).expect("Cannot be empty!");