Reaction Auto-Mapping Tool doesn't work for single and cascade reactions with Multi-Tailed Arrow

[ivanmaslow]

Steps to Reproduce 1 - Single Reaction

1. Add single reaction 2x1 to Canvas from KET:
   ket-2x1.zip
   
2. Click on the Reaction Mapping Tool and use Auto-Mapping Tool

Actual behavior

• Auto-Mapping Tool is disabled
  

Expected behavior

• It has to be enabled and work with Multi-Tailed arrow as in case when reaction with plus on Canvas:
  

Steps to Reproduce 2 - Cascade Reaction - additional issue can be created if it's not possible to fix them together

1. Add cascade reaction 2-1-1 to Canvas from KET:
   ket-2-1-1 (1).zip
   
2. Click on the Reaction Mapping Tool and use Auto-Mapping Tool
3. Select any option (Discard, Keep, Alter)

Actual behavior

• Error "array: invalid index 1 (size=0)" appears:
  

Expected behavior

• Error doesn't appear, it should work as for several single reactions: 2:1 and 1:1

Environment details:

• RC SA env
• [Version 2.26.0-rc.2] Build at 2024-10-14; 19:59:03
• Indigo Version 1.25.0-rc.2.0-g867ae250b-wasm32-wasm-clang-19.0.0
• Desktop, Windows 11 Enterprise
• Chrome Version 129.0.6668.101 (Official Build) (64-bit)

Additional context

• This test case is added to xls and have to be automated
• Issue is detected during retesting of Indigo functions doesn't work prorerly: Aromatize, Dearomatize, Layout, Clean Up, Hydrogens, Auto-Mapping Tool #2422, it's related to this task - Import/export multi-tails in KET #2236