Add seasonal effects for Pi Day, Pride, Rain, and Storm; enhance existing styles

- Introduced new CSS and JS files for Pi Day, Pride, Rain, and Storm effects.
- Updated existing seasonal styles (e.g., Halloween, Hearts, Resurrection) to improve performance with 'contain: layout paint'.
- Enhanced animations for seasonal effects, including adjustments to keyframes and element creation logic.
- Added configuration options for new effects in the main seasonals.js file.
- Updated test-site.html to include new seasonal options in the dropdown.

Jellyfin.Plugin.Seasonals/Web/hearts.css

@@ -8,6 +8,7 @@
     height: 100%;
     pointer-events: none;
     z-index: 10;
+    contain: layout paint;
 }
 
 .heart {
@@ -32,11 +33,11 @@
 
 @-webkit-keyframes heart-fall {
     0% {
-        bottom: -10%
+        bottom: -10%;
     }
 
     100% {
-        bottom: 100%
+        bottom: 110%;
     }
 }
 
@@ -56,11 +57,11 @@
 
 @keyframes heart-fall {
     0% {
-        bottom: -10%
+        bottom: -10%;
     }
 
     100% {
-        bottom: 100%
+        bottom: 110%;
     }
 }