[MM-26812] Add support for resumable file uploads (#15252)

* Implement AppendFile for FileBackend

* Split test into subtests

* [MM-26812] Add support for resumable file uploads (#15252)

* Implement UploadSession

* Implement UploadSessionStore

* Add error strings

* Implement resumable file uploads

* Add UploadType

* Fix retry layer tests

* Regenerate store layers

* Fix store error handling

* Use base for filename

* Prevent concurrent uploads on the same upload session

* Fix erroneus error string

* Improve error handling

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

* Fix translations

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

i18n/en.json

@@ -1312,6 +1312,22 @@
     "id": "api.emoji.upload.open.app_error",
     "translation": "Unable to create the emoji. An error occurred when trying to open the attached image."
   },
+  {
+    "id": "api.file.append_file.no_exist.app_error",
+    "translation": "File does not exist."
+  },
+  {
+    "id": "api.file.append_file.opening.app_error",
+    "translation": "Encountered an error opening the file."
+  },
+  {
+    "id": "api.file.append_file.s3.app_error",
+    "translation": "Encountered an error appending to a file in S3."
+  },
+  {
+    "id": "api.file.append_file.writing.app_error",
+    "translation": "Encountered an error writing to S3."
+  },
   {
     "id": "api.file.attachments.disabled.app_error",
     "translation": "File attachments have been disabled on this server."
@@ -2686,6 +2702,14 @@
     "id": "api.upgrade_to_enterprise_status.signature.app_error",
     "translation": "Mattermost was unable to upgrade to Enterprise Edition. The digital signature of the downloaded binary file could not be verified."
   },
+  {
+    "id": "api.upload.get_upload.forbidden.app_error",
+    "translation": "Failed to get upload."
+  },
+  {
+    "id": "api.upload.upload_data.invalid_content_length",
+    "translation": "Invalid Content-Length."
+  },
   {
     "id": "api.user.activate_mfa.email_and_ldap_only.app_error",
     "translation": "MFA is not available for this account type."
@@ -2850,6 +2874,10 @@
     "id": "api.user.get_authorization_code.unsupported.app_error",
     "translation": "Unsupported OAuth service provider."
   },
+  {
+    "id": "api.user.get_uploads_for_user.forbidden.app_error",
+    "translation": "Failed to get uploads."
+  },
   {
     "id": "api.user.get_user_by_email.permissions.app_error",
     "translation": "Unable to get user by email."
@@ -4886,6 +4914,54 @@
     "id": "app.terms_of_service.get.no_rows.app_error",
     "translation": "No terms of service found."
   },
+  {
+    "id": "app.upload.create.cannot_upload_to_deleted_channel.app_error",
+    "translation": "Cannot upload to a deleted channel."
+  },
+  {
+    "id": "app.upload.create.incorrect_channel_id.app_error",
+    "translation": "Cannot upload to the specified channel."
+  },
+  {
+    "id": "app.upload.create.save.app_error",
+    "translation": "Failed to save upload."
+  },
+  {
+    "id": "app.upload.create.upload_too_large.app_error",
+    "translation": "Unable to upload file. File is too large."
+  },
+  {
+    "id": "app.upload.get.app_error",
+    "translation": "Failed to get upload."
+  },
+  {
+    "id": "app.upload.get_for_user.app_error",
+    "translation": "Failed to get uploads for user."
+  },
+  {
+    "id": "app.upload.upload_data.concurrent.app_error",
+    "translation": "Unable to upload data from more than one request."
+  },
+  {
+    "id": "app.upload.upload_data.first_part_too_small.app_error",
+    "translation": "Failed to upload data. First part must be at least {{.Size}} Bytes."
+  },
+  {
+    "id": "app.upload.upload_data.large_image.app_error",
+    "translation": "{{.Filename}} dimensions ({{.Width}} by {{.Height}} pixels) exceed the limits."
+  },
+  {
+    "id": "app.upload.upload_data.read_file.app_error",
+    "translation": "Failed to read a file."
+  },
+  {
+    "id": "app.upload.upload_data.save.app_error",
+    "translation": "Failed to save file info."
+  },
+  {
+    "id": "app.upload.upload_data.update.app_error",
+    "translation": "Failed to update the upload session."
+  },
   {
     "id": "app.user.convert_bot_to_user.app_error",
     "translation": "Unable to convert bot to user."
@@ -7074,6 +7150,42 @@
     "id": "model.token.is_valid.size",
     "translation": "Invalid token."
   },
+  {
+    "id": "model.upload_session.is_valid.channel_id.app_error",
+    "translation": "Invalid value for ChannelId."
+  },
+  {
+    "id": "model.upload_session.is_valid.create_at.app_error",
+    "translation": "Invalid value for CreateAt"
+  },
+  {
+    "id": "model.upload_session.is_valid.file_offset.app_error",
+    "translation": "Invalid value for FileOffset"
+  },
+  {
+    "id": "model.upload_session.is_valid.file_size.app_error",
+    "translation": "Invalid value for FileSize"
+  },
+  {
+    "id": "model.upload_session.is_valid.filename.app_error",
+    "translation": "Invalid value for Filename"
+  },
+  {
+    "id": "model.upload_session.is_valid.id.app_error",
+    "translation": "Invalid value for Id"
+  },
+  {
+    "id": "model.upload_session.is_valid.path.app_error",
+    "translation": "Invalid value for Path"
+  },
+  {
+    "id": "model.upload_session.is_valid.type.app_error",
+    "translation": "Invalid value for Type"
+  },
+  {
+    "id": "model.upload_session.is_valid.user_id.app_error",
+    "translation": "Invalid Value for UserId"
+  },
   {
     "id": "model.user.is_valid.auth_data.app_error",
     "translation": "Invalid auth data."