Macro: When adding new nucleotides to the beginning of a row, the order of the chains changes in the Sequence mode

[ViktoriaTkacheva]

Steps to Reproduce

1. Switch to the Macro mode - Sequence mode
2. Add any four chains to the canvas (for example, AAA, TTT, UUU, CCC)
   
3. At the very beginning of the second chain, enter U
   

Actual behavior
If you add at least one new nucleotide at the very beginning of the second or any subsequent chain (but not the first or the last), the chains randomly change places (the second takes the place of the third, and the third takes the place of the fourth)
Also,
The same behavior is observed when at the very beginning of the chain we insert a copied fragment.

Expected behavior
When adding new nucleotides at the very beginning of any chain, the chains are not swapped

Desktop (please complete the following information):

• OS: Windows 10 Pro (version 22H2) x64
• Browser: Сhrome
• Version: (122.0.6261.112) x64

Ketcher version 2.20.0-rc.1

Issue found while testing #3650

Screenshots

2024-03-26_14h08_09.mp4

[ViktoriaTkacheva]

The same behavior is observed when at the very beginning of the chain we insert a copied fragment

[Zhirnoff]

Test added to the automation table.

[Zhirnoff]

Test automated.

[AlexeyGirin]

Verified.

• Indigo Toolkit Version 1.21.0-dev.3.0-g6f55c664-wasm32-wasm-clang-12.0.0
• Ketcher Version 2.21.0-rc.2 Build at 2024-05-20; 05:30:45
• Chrome Version 124.0.6367.201 (Official Build) (64-bit)
• Windows 10