Add Cover card and implement block

Assets/Battle/Cards/CardCover.cs

@@ -0,0 +1,17 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class CardCover : BaseCard
+{
+    public CardCover() : base(CardId.Cover, "Cover", 1, CardType.Action, "Block 3 damage on another target ally.") {
+
+    }
+
+    public override IEnumerator Use(BattlePlayerControls playerControls) {
+        List<BattleParticipant> target = new List<BattleParticipant>();
+        yield return playerControls.StartCoroutine(playerControls.ChooseTarget((t) => {target.Add(t);}));
+        Debug.Log("Covering " + target[0]);
+        target[0].AddBlock(3);
+    }
+}

Assets/Battle/Cards/CardCover.cs.meta

@@ -0,0 +1,11 @@
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