Refactor page content generators

CHDataManagement/Generator/Commands/LabelsCommand.swift

@@ -0,0 +1,31 @@
+
+struct LabelsCommand: CommandProcessor {
+
+    static let commandType: CommandType = .labels
+
+    let content: Content
+
+    let results: PageGenerationResults
+
+    init(content: Content, results: PageGenerationResults, language: ContentLanguage) {
+        self.content = content
+        self.results = results
+    }
+
+    func process(_ arguments: [String], markdown: Substring) -> String {
+        let labels: [ContentLabel] = arguments.compactMap { arg in
+            let parts = arg.components(separatedBy: "=")
+            guard parts.count == 2 else {
+                invalid(markdown)
+                return nil
+            }
+            guard let icon = PageIcon(rawValue: parts[0].trimmed) else {
+                invalid(markdown)
+                return nil
+            }
+            results.require(icon: icon)
+            return .init(icon: icon, value: parts[1])
+        }
+        return ContentLabels(labels: labels).content
+    }
+}