Add error handling to contrainer removal (#3424)

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Task/Issue URL:
https://app.asana.com/0/856498667320406/1207976962313181/f

**Description**:

Make sure the containers created recently or the ones that fail to be
removed are given another chance to be cleaned.

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**Steps to test this PR**:

Open the app, navigate to site that sets cookies, refresh, press fire
button.

Smoke test data clearing, auto clear - both on app restart and time
based one.
Test fireproofing on usage and after restart.

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you expect the reviewer to test, then delete configurations you *know*
do not need explicit testing.

Using a simulator where a physical device is unavailable is acceptable.
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**Definition of Done (Internal Only)**:

* [ ] Does this PR satisfy our [Definition of
Done](https://app.asana.com/0/1202500774821704/1207634633537039/f)?

**OS Testing**:

* [ ] iOS 15
* [ ] iOS 16
* [ ] iOS 17

**Theme Testing**:

* [ ] Light theme
* [ ] Dark theme

---
###### Internal references:
[Software Engineering
Expectations](https://app.asana.com/0/59792373528535/199064865822552)
[Technical Design
Template](https://app.asana.com/0/59792373528535/184709971311943)

Core/WebCacheManager.swift

@@ -82,14 +82,29 @@ public class WebCacheManager {
                       dataStoreIdManager: DataStoreIdManaging = DataStoreIdManager.shared) async {
 
         var cookiesToUpdate = [HTTPCookie]()
+        var leftoverContainerIDs = [UUID]()
         if #available(iOS 17, *) {
-            cookiesToUpdate += await containerBasedClearing(storeIdManager: dataStoreIdManager) ?? []
+            let result = await containerBasedClearing(storeIdManager: dataStoreIdManager)
+            cookiesToUpdate += result.cookies
+            leftoverContainerIDs = result.leftoverContainerIDs
         }
 
         // Perform legacy clearing to migrate to new container
         cookiesToUpdate += await legacyDataClearing() ?? []
 
         cookieStorage.updateCookies(cookiesToUpdate, keepingPreservedLogins: logins)
+
+        // Attempt to clean up leftover stores again after a delay
+        // This should not be a problem as these containers are not supposed to be used anymore.
+        // If this fails, we are going to still clean them next time as WebKit keeps track of all stores for us.
+        if #available(iOS 17, *), !leftoverContainerIDs.isEmpty {
+            Task {
+                try? await Task.sleep(for: .seconds(3))
+                for uuid in leftoverContainerIDs {
+                    try? await WKWebsiteDataStore.remove(forIdentifier: uuid)
+                }
+            }
+        }
     }
 
 }
@@ -113,18 +128,27 @@ extension WebCacheManager {
     }
 
     @available(iOS 17, *)
-    private func containerBasedClearing(storeIdManager: DataStoreIdManaging) async -> [HTTPCookie]? {
+    private func containerBasedClearing(storeIdManager: DataStoreIdManaging) async -> (cookies: [HTTPCookie],
+                                                                                       leftoverContainerIDs: [UUID]) {
         guard let containerId = storeIdManager.currentId else {
             storeIdManager.invalidateCurrentIdAndAllocateNew()
-            return []
+            return ([], [])
         }
         storeIdManager.invalidateCurrentIdAndAllocateNew()
 
+        var leftoverContainerIDs = [UUID]()
+
         var dataStore: WKWebsiteDataStore? = WKWebsiteDataStore(forIdentifier: containerId)
-        let cookies = await dataStore?.httpCookieStore.allCookies()
+        let cookies = await dataStore?.httpCookieStore.allCookies() ?? []
         dataStore = nil
 
         var uuids = await WKWebsiteDataStore.allDataStoreIdentifiers
+
+        // There may be a timing issue related to fetching current container, so append previous UUID as a precaution
+        if uuids.firstIndex(of: containerId) == nil {
+            uuids.append(containerId)
+        }
+
         if let newContainerID = storeIdManager.currentId,
             let newIdIndex = uuids.firstIndex(of: newContainerID) {
             assertionFailure("Attempted to cleanup current Data Store")
@@ -133,11 +157,15 @@ extension WebCacheManager {
 
         let previousLeftOversCount = max(0, uuids.count - 1) // -1 because one store is expected to be cleared
         for uuid in uuids {
-            try? await WKWebsiteDataStore.remove(forIdentifier: uuid)
+            do {
+                try await WKWebsiteDataStore.remove(forIdentifier: uuid)
+            } catch {
+                leftoverContainerIDs.append(uuid)
+            }
         }
         await checkForLeftBehindDataStores(previousLeftOversCount: previousLeftOversCount)
 
-        return cookies
+        return (cookies, leftoverContainerIDs)
     }
 
     private func legacyDataClearing() async -> [HTTPCookie]? {