feat(quote): enhance QuoteBlock and QuoteCarouselBlock components

- Updated QuoteBlock to support a new "center" variant for text alignment.
- Modified QuoteCarouselBlock to include an option for displaying navigation arrows.
- Enhanced type definitions for quote-related data structures to accommodate new features.
- Improved styling and layout handling for better visual presentation of quotes.

src/lib/block-types.ts

@@ -136,7 +136,7 @@ export interface QuoteBlockData {
   _slug?: string;
   quote?: string;
   author?: string;
-  variant?: "left" | "right";
+  variant?: "left" | "right" | "center";
   layout?: BlockLayout;
 }
 
@@ -151,11 +151,12 @@ export interface QuoteCarouselBlockData {
         _slug?: string;
         quote?: string;
         author?: string;
-        variant?: "left" | "right";
+        variant?: "left" | "right" | "center";
       }
   >;
   autoRotate?: boolean;
   intervalSeconds?: number;
+  showArrows?: boolean;
   layout?: BlockLayout;
 }