PLT-3105 Files table migration (#4068)

* Implemented initial changes for files table

* Removed *_benchmark_test.go files

* Re-implemented GetPublicFile and added support for old path

* Localization for files table

* Moved file system code into utils package

* Finished server-side changes and added initial upgrade script

* Added getPostFiles api

* Re-add Extension and HasPreviewImage fields to FileInfo

* Removed unused translation

* Fixed merge conflicts left over after permissions changes

* Forced FileInfo.extension to be lower case

* Changed FileUploadResponse to contain the FileInfos instead of FileIds

* Fixed permissions on getFile* calls

* Fixed notifications for file uploads

* Added initial version of client code for files changes

* Permanently added FileIds field to Post object and removed Post.HasFiles

* Updated PostStore.Update to be usable in more circumstances

* Re-added Filenames field and switched file migration to be entirely lazy-loaded

* Increased max listener count for FileStore

* Removed unused fileInfoCache

* Moved file system code back into api

* Removed duplicate test case

* Fixed unit test running on ports other than 8065

* Renamed HasPermissionToPostContext to HasPermissionToChannelByPostContext

* Refactored handleImages to make it more easily understandable

* Renamed getPostFiles to getFileInfosForPost

* Re-added pre-FileIds posts to analytics

* Changed files to be saved as their ids as opposed to id/filename.ext

* Renamed FileInfo.UserId to FileInfo.CreatorId

* Fixed detection of language in CodePreview

* Fixed switching between threads in the RHS not loading new files

* Add serverside protection against a rare bug where the client sends the same file twice for a single post

* Refactored the important parts of uploadFile api call into a function that can be called without a web context

store/sql_store.go

@@ -81,6 +81,7 @@ type SqlStore struct {
 	recovery      PasswordRecoveryStore
 	emoji         EmojiStore
 	status        StatusStore
+	fileInfo      FileInfoStore
 	SchemaVersion string
 }
 
@@ -129,6 +130,7 @@ func NewSqlStore() Store {
 	sqlStore.recovery = NewSqlPasswordRecoveryStore(sqlStore)
 	sqlStore.emoji = NewSqlEmojiStore(sqlStore)
 	sqlStore.status = NewSqlStatusStore(sqlStore)
+	sqlStore.fileInfo = NewSqlFileInfoStore(sqlStore)
 
 	err := sqlStore.master.CreateTablesIfNotExists()
 	if err != nil {
@@ -155,6 +157,7 @@ func NewSqlStore() Store {
 	sqlStore.recovery.(*SqlPasswordRecoveryStore).CreateIndexesIfNotExists()
 	sqlStore.emoji.(*SqlEmojiStore).CreateIndexesIfNotExists()
 	sqlStore.status.(*SqlStatusStore).CreateIndexesIfNotExists()
+	sqlStore.fileInfo.(*SqlFileInfoStore).CreateIndexesIfNotExists()
 
 	sqlStore.preference.(*SqlPreferenceStore).DeleteUnusedFeatures()
 
@@ -643,6 +646,10 @@ func (ss SqlStore) Status() StatusStore {
 	return ss.status
 }
 
+func (ss SqlStore) FileInfo() FileInfoStore {
+	return ss.fileInfo
+}
+
 func (ss SqlStore) DropAllTables() {
 	ss.master.TruncateTables()
 }