Add pub to xcm::v4::PalletInfo (#4976)

v3 PalletInfo had the fields public, but not v4. Any reason why?
I need the PalletInfo fields public so I can read the values and do some
logic based on that at Polimec
@franciscoaguirre 

If this could be backported would be highly appreciated 🙏🏻

---------

Co-authored-by: Adrian Catangiu <adrian@parity.io>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

polkadot/xcm/src/v4/mod.rs

@@ -231,15 +231,15 @@ parameter_types! {
 #[derive(Clone, Eq, PartialEq, Encode, Decode, Debug, TypeInfo, MaxEncodedLen)]
 pub struct PalletInfo {
 	#[codec(compact)]
-	index: u32,
-	name: BoundedVec<u8, MaxPalletNameLen>,
-	module_name: BoundedVec<u8, MaxPalletNameLen>,
+	pub index: u32,
+	pub name: BoundedVec<u8, MaxPalletNameLen>,
+	pub module_name: BoundedVec<u8, MaxPalletNameLen>,
 	#[codec(compact)]
-	major: u32,
+	pub major: u32,
 	#[codec(compact)]
-	minor: u32,
+	pub minor: u32,
 	#[codec(compact)]
-	patch: u32,
+	pub patch: u32,
 }
 
 impl TryInto<OldPalletInfo> for PalletInfo {

prdoc/pr_4976.prdoc

@@ -0,0 +1,15 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Add pub to xcm::v4::PalletInfo
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      Forgot to make v4 PalletInfo fields public. Without them we cannot make use of the struct.
+
+crates:
+  - name: staging-xcm
+    bump: patch
+    validate: false
+