Create Antisense Strand option is missing from context menu even if base with R3-R1 present in the selection

[AlexeyGirin]

Steps to Reproduce

1. Go to Macro - Snake mode
2. Load from HELM using paste from clipboard: RNA1{([25moe3],[5A6])(A+C+G+T)P}$$$$V2.0
   
3. Select all monomers on the canvas and call context menu

Actual behavior
Create Antisense Strand option is missing

Expected behavior
Create Antisense Strand option is present but disabled

As per requirement:

1.1. If there is a sugar in the backbone and it is connected to the a base via R3-R1, but the base is not a "sense base" form the table above, the "Create Antisense Strand" option should appear, but be disabled.

Try the following cases:
RNA1{([25moe3],[5A6])(A+C+G+T)P}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C+G+T)([bnn],[bP])}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C+G+T)P}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C+G+T)([bnn],[bP])}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C+G+T)([bnn]+[bP])}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C+G+T)([bnn]+[bP])}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C+G+U)P}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C+G+U)([bnn],[bP])}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C+G+U)P}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C+G+U)([bnn],[bP])}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C+G+U)([bnn]+[bP])}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C+G+U)([bnn]+[bP])}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C)P}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C)([bnn],[bP])}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C)P}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C)([bnn],[bP])}$$$$V2.0
RNA1{([25moe3],[5A6])(A+C)([bnn]+[bP])}$$$$V2.0
RNA1{([25moe3]+[5A6])(A+C)([bnn]+[bP])}$$$$V2.0

Versions

• Ketcher Version 2.28.0-rc.3 Build at 2024-12-11; 14:32:57
• Indigo Version 1.27.0-rc.1.0-g8d656a341-wasm32-wasm-clang-19.0.0
• Chrome Version 131.0.6778.109 (Official Build) (64-bit)
• Win10

Issue found while testing - #5678