MM-53747: Create job to encode older image paths (#24073)

Bifrost now encodes all image paths. Due to this
one-way translation, we need to encode all the older
image paths as well.

After this is done, we can remove the double-lookup.

https://mattermost.atlassian.net/browse/MM-53747

```release-note
NONE
```

Co-authored-by: Mattermost Build <build@mattermost.com>

server/platform/services/searchengine/bleveengine/indexer/indexing_job.go

@@ -404,7 +404,7 @@ func (worker *BleveIndexerWorker) IndexFilesBatch(progress IndexingProgress) (In
 	tries := 0
 	for files == nil {
 		var err error
-		files, err = worker.jobServer.Store.FileInfo().GetFilesBatchForIndexing(progress.LastEntityTime, progress.LastFileID, *worker.jobServer.Config().BleveSettings.BatchSize)
+		files, err = worker.jobServer.Store.FileInfo().GetFilesBatchForIndexing(progress.LastEntityTime, progress.LastFileID, true, *worker.jobServer.Config().BleveSettings.BatchSize)
 		if err != nil {
 			if tries >= 10 {
 				return progress, model.NewAppError("IndexFilesBatch", "app.post.get_files_batch_for_indexing.get.app_error", nil, "", http.StatusInternalServerError).Wrap(err)