Add support for <details> and <summary> tags (#6077)

ElementX/Sources/Other/HTMLParsing/HTMLFixtures.swift

@@ -19,6 +19,7 @@ nonisolated enum HTMLFixtures: String, CaseIterable {
     case wideCodeBlock
     case unorderedList
     case orderedList
+    case details
     
     var rawValue: String {
         switch self {
@@ -123,6 +124,13 @@ nonisolated enum HTMLFixtures: String, CaseIterable {
             <li>Skittles</li>
             </ol>
             """
+        case .details:
+            """
+            Text before the details\
+            <details><summary>Expand me</summary><p>Hidden <b>content</b> with a <a href="https://www.matrix.org">link</a> in it.</p></details>\
+            <details><p>These details have no summary.</p></details>\
+            Text after the details
+            """
         }
     }
 }