Add parameter allowed encoding to error descriptions (#795)

Task/Issue URL: https://app.asana.com/0/1203790657351911/1207097497487052/f
iOS PR: duckduckgo/iOS#2781
macOS PR: duckduckgo/macos-browser#2691
What kind of version bump will this require?: Patch

Sources/Common/Extensions/URLExtension.swift

@@ -425,7 +425,7 @@ extension URL {
 
 }
 
-fileprivate extension CharacterSet {
+public extension CharacterSet {
 
     /**
      * As per [RFC 3986](https://www.rfc-editor.org/rfc/rfc3986#section-2.2).

Sources/PrivacyDashboard/BrokenSiteReporting/BrokenSiteReport.swift

@@ -236,11 +236,7 @@ public struct BrokenSiteReport {
         }
 
         if let errors {
-            let errorDescriptions: [String] = errors.map {
-                let error = $0 as NSError
-                return "\(error.code) - \(error.domain):\(error.localizedDescription)"
-            }
-            result["errorDescriptions"] = errorDescriptions.joined(separator: ",")
+            result["errorDescriptions"] = encodeErrors(errors)
         }
 
         if let jsPerformance {
@@ -256,4 +252,14 @@ public struct BrokenSiteReport {
         return result
     }
 
+    private func encodeErrors(_ errors: [Error]) -> String {
+        let errorDescriptions: [String] = errors.map {
+            let error = $0 as NSError
+            return "\(error.code) - \(error.domain):\(error.localizedDescription)"
+        }
+        let jsonString = try? String(data: JSONSerialization.data(withJSONObject: errorDescriptions), encoding: .utf8)!
+        let encodedString = jsonString?.addingPercentEncoding(withAllowedCharacters: .urlQueryParameterAllowed)
+        return encodedString ?? ""
+    }
+
 }