Add more file properties, organize storage, add video block

CHDataManagement/Page Elements/ContentElements/VersionedVideo.swift

@@ -0,0 +1,19 @@
+
+struct VersionedVideo: HtmlProducer {
+
+    let sources: [VideoBlock.Source]
+
+    let options: [VideoBlock.Option]
+
+    func populate(_ result: inout String) {
+        result += "<video\(optionString)>Video not supported."
+        for source in sources.sorted(using: { $0.type.order }) {
+            result += "<source src='\(source.file.absoluteUrl)' type='\(source.type.mimeType)'>"
+        }
+        result += "</video>"
+    }
+
+    private var optionString: String {
+        options.map { " " + $0.rawValue }.joined()
+    }
+}