Remove possibly AI background, use shader for BG instead. Remove placeholder Rare Sword, fix missing Avarice name

src/items/weapons/resources/RareSword.tres

@@ -1,19 +0,0 @@
-[gd_resource type="Resource" script_class="WeaponInfo" load_steps=3 format=3 uid="uid://b4oxsf4k3nr43"]
-
-[ext_resource type="Script" path="res://src/items/weapons/WeaponInfo.cs" id="1_oqgv2"]
-[ext_resource type="Texture2D" uid="uid://wd6jh5q51e4k" path="res://src/items/weapons/models/sword.png" id="1_rlq8c"]
-
-[resource]
-script = ExtResource("1_oqgv2")
-Damage = 7
-Luck = 0.05
-AttackSpeed = 1.0
-TelluricDamageBonus = 0.0
-AeolicDamageBonus = 0.0
-BaseHydricDamageBonus = 0.0
-IgneousDamageBonus = 0.0
-FerrumDamageBonus = 0.0
-WeaponTags = Array[int]([])
-Name = "Rare sword"
-Description = "Rare"
-Texture = ExtResource("1_rlq8c")