perf: Migrate Veteran Reward gumps to DynamicGump/StaticGump (#2415)

## Summary

Migrates 16 player-facing legacy `Gump` subclasses in the Veteran Rewards system to `DynamicGump` or `StaticGump<T>`, renames every nested `InternalGump`/`ConfirmGump` to system-prefixed names, and updates external callers to use new static `DisplayTo` entry points.

### Reward chain (Engines/Veteran Rewards)

| Gump | Base type | Reasoning |
|---|---|---|
| `RewardNoticeGump` | `StaticGump<T>` | Fixed layout |
| `RewardChoiceGump` | `DynamicGump` | Layout shape varies (per-player categories, entries, pages) |
| `RewardConfirmGump` | `DynamicGump` | `entry.Name` is a dynamic cliloc per reward (cliloc rule) |
| `RewardOptionGump` | `DynamicGump` | Title cliloc and per-option clilocs are dynamic (cliloc rule) |
| `RewardDemolitionGump` | `DynamicGump` | `question` cliloc is dynamic per caller (cliloc rule) |

### Statue (Engines/Veteran Rewards/Character Statue Maker)

| Gump | Base type | Reasoning |
|---|---|---|
| `CharacterStatueGump` | `DynamicGump` | Pose/Direction/Material labels are dynamic clilocs (cliloc rule) |
| `CharacterPlinthGump` | `DynamicGump` | `statue.Name`, sculpted-on date, and statue-type cliloc are dynamic (cliloc rule) |

### Decorations (Items/Special/Veteran Rewards) — every `InternalGump` renamed

| Original | New name | Base type | Reasoning |
|---|---|---|---|
| `Banner.InternalGump` | `BannerGump` | `StaticGump<T>` | Fully fixed item-id picker over `Start..End` range |
| `Brazier.InternalGump` | `BrazierGump` | `StaticGump<T>` | Fixed two-item picker |
| `Cannon.InternalGump` | `CannonGump` | `DynamicGump` | `keg.Validate()` value passed as `~1_CHARGES~` arg (cliloc-arg rule) |
| `DecorativeShield.InternalGump` | `DecorativeShieldGump` | `StaticGump<T>` | Fixed item picker over a constant range |
| `DecorativeShield.FacingGump` | `DecorativeShieldFacingGump` | `DynamicGump` | Item ids depend on instance state |
| `HangingSkeleton.InternalGump` | `HangingSkeletonGump` | `StaticGump<T>` | Fixed item picker (5 hard-coded ids) |
| `PottedCactus.InternalGump` | `PottedCactusGump` | `StaticGump<T>` | Fixed 6-item picker |
| `StoneAnkh.InternalGump` | `StoneAnkhGump` | `StaticGump<T>` | Fixed two-direction picker |
| `WallBanner.InternalGump` | `WallBannerGump` | `StaticGump<T>` | Fixed 30-banner picker across 5 pages |
| `WeaponEngravingTool.InternalGump` | `WeaponEngravingToolGump` | `StaticGump<T>` | Fixed text-entry dialog |
| `WeaponEngravingTool.ConfirmGump` | `WeaponEngravingToolConfirmGump` | `DynamicGump` | Layout branches on `guildmaster != null` |

### External callers updated

`RewardSystem`, `CharacterStatue`, `FireFliesDeed`, `FlamingHead`, `Banner`, `DecorativeShield`, `HangingSkeleton`, `StoneAnkh` (RewardDemolitionGump callers); `AnkhOfSacrifice`, `Cannon`, `MiningCart`, `MinotaurStatue`, `TreeStump` (RewardOptionGump callers); `TinkerGuildmaster` (engraver confirm gump).

The pre-existing `FacingGump` inside `Banner.cs` (already `DynamicGump`) was left as-is — it is private, nested inside `InternalTarget`, and never referenced outside.

Projects/UOContent/Engines/Veteran Rewards/RewardSystem.cs

@@ -595,7 +595,7 @@ namespace Server.Engines.VeteranRewards
 
             if (cur < max)
             {
-                pm.SendGump(new RewardNoticeGump(pm));
+                RewardNoticeGump.DisplayTo(pm);
             }
         }
     }