As discussed with decision makes, it's better to move 16th and 17th sub issue from ZBXNEXT-7951
Import fails in the same place by different scenarios, more investigation required.

Steps to reproduce first scenario:
1) Create template with one item and add two unique host groups;
2) Export this template and open with editor;
3) Start importing this file, while it's open in editor;
4) Upload file and then change host groups name;
5) Save file, which is uploaded and at the same time edited;
6) Import file;

Expected:

Actual:

**

Steps to reproduce second scenario:
1) Start process of importing templates;
2) Open console and delete import template action SID;
3) Continue process of importing templates by pressing "Import"

Expected:

Actual:

Console errors shows, and import process runs endlessly;