[MM-53245] export/import: add Props to the replies (#29531)

server/channels/app/imports/import_types.go

@@ -183,10 +183,11 @@ type ReactionImportData struct {
 type ReplyImportData struct {
 	User *string `json:"user"`
 
-	Type     *string `json:"type"`
-	Message  *string `json:"message"`
-	CreateAt *int64  `json:"create_at"`
-	EditAt   *int64  `json:"edit_at"`
+	Type     *string                `json:"type"`
+	Message  *string                `json:"message"`
+	Props    *model.StringInterface `json:"props"`
+	CreateAt *int64                 `json:"create_at"`
+	EditAt   *int64                 `json:"edit_at"`
 
 	FlaggedBy   *[]string               `json:"flagged_by,omitempty"`
 	Reactions   *[]ReactionImportData   `json:"reactions,omitempty"`

server/channels/app/imports/import_validators.go

@@ -474,6 +474,19 @@ func ValidateReplyImportData(data *ReplyImportData, parentCreateAt int64, maxPos
 		mlog.Warn("Reply CreateAt is before parent post CreateAt", mlog.Int("reply_create_at", *data.CreateAt), mlog.Int("parent_create_at", parentCreateAt))
 	}
 
+	if data.Props != nil && utf8.RuneCountInString(model.StringInterfaceToJSON(*data.Props)) > model.PostPropsMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.props_too_large.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Reactions != nil {
+		for _, reaction := range *data.Reactions {
+			reaction := reaction
+			if err := ValidateReactionImportData(&reaction, *data.CreateAt); err != nil {
+				return err
+			}
+		}
+	}
+
 	return nil
 }