RXN files: structure is missing when "Paste from clipboard" or "Open from file" if reaction consists of two or more reaction arrows and structures.

[Zhirnoff]

Steps to Reproduce

1. Open Ketcher v2.5.2
2. Add a reaction with multiple (more than one reaction arrow) as shown in the image
3. Save file in MDL Rxnfile V2000 and MDL Rxnfile V3000
4. Paste files from clipboard or open saved files from saved directory.

Expected behavior
Structure is correctly opens from saved files. Keep only first reaction arrow and keep all structures (all intermediate structures should be products and the arrow is replaced by a plus)

Actual behavior
In MDL Rxnfile V2000 the arrow disappears, and when opening MDL Rxnfile V3000 the arrow and structure disappear

Attachments

Indigo/Bingo version
Indigo Toolkit
Version 1.7.4.0-g86f1ef175-x86_64-linux-gnu-11.2.1

Additional context
Indigo issue: epam/Indigo#870

[vitaepam]

While writing test in this task #3181 found out like it's reproducing again
At least for V2000 RXN files. Maybe it's somehow expected behaviour. @Zhirnoff need your clarifications