move group actions to sidebar and add invite link copying

crates/nip29/src/group.rs

@@ -145,6 +145,10 @@ impl Group {
             .map(SharedString::from)
     }
 
+    pub fn total_members(&self) -> usize {
+        self.members.len()
+    }
+
     pub fn members(&self) -> &GroupMembers {
         &self.members
     }

crates/nip29/src/protocol.rs

@@ -544,6 +544,15 @@ impl GroupMembers {
     pub fn iter(&self) -> impl Iterator<Item = &PublicKey> {
         self.0.iter()
     }
+
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]