Ambiguous DNA bases (N, D, H, W) wrongly converted to DNA bases on antisense creation

[AlexeyGirin]

Steps to Reproduce

1. Go to Macro mode - Snake mode
2. Load from HELM: RNA1{R(A,C,G,T)P.R(A,G,T)P.R(A,C,T)P.R(A,T)P}$$$$V2.0
   
3. Create antisense for that chain

Actual behavior
System creates all DNA bases instead of RNA ones in antisense chain.
HELM export result: RNA1{R(A,C,G,T)P.R(A,G,T)P.R(A,C,T)P.R(A,T)P}|RNA2{R(A,C,G,T)P.R(A,C,T)P.R(A,G,T)P.R(A,T)P}$RNA1,RNA2,2:pair-2:pair|RNA1,RNA2,5:pair-5:pair|RNA1,RNA2,8:pair-8:pair|RNA1,RNA2,11:pair-11:pair$$$V2.0

Expected behavior
System creates all RNA bases
HELM export result: RNA1{R(A,C,G,T)P.R(A,G,T)P.R(A,C,T)P.R(A,T)P}|RNA2{R(A,C,G,U)P.R(A,C,U)P.R(A,G,U)P.R(A,U)P}$RNA1,RNA2,2:pair-2:pair|RNA1,RNA2,5:pair-5:pair|RNA1,RNA2,8:pair-8:pair|RNA1,RNA2,11:pair-11:pair$$$V2.0

As per requirement:

Complementary bases

Sense base	Antisense base
N (ambiguous DNA base) and N (ambiguous RNA base)	N (ambiguous RNA base)
D (ambiguous DNA base) and D (ambiguous RNA base)	H (ambiguous RNA base)
H (ambiguous DNA base) and H (ambiguous RNA base)	D (ambiguous RNA base)
W (ambiguous DNA base) and W (ambiguous RNA base)	W (ambiguous RNA base)

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

[AlexeyGirin]

Verified.

• Ketcher Version 3.0.0-rc.7 Build at 2025-02-05; 16:27:42
• Indigo Version 1.28.0-rc.3.0-gd5bcc27cb-wasm32-wasm-clang-19.0.0
• Chrome Version 133.0.6943.54 (Official Build) (64-bit)
• Win10