Pasting a large molecule doesn't work in Ketcher (works slow)

[AlexeyGirin]

Original issue on ketcher side: epam/ketcher#4093

Steps to Reproduce

1. Open Ketcher edito
2. Paste a large molecule SMILES eg.: CCCC(NC(=O)C1CCCN1C(=O)C(CC(C)C)NC(=O)C(Cc1ccccc1)NC(=O)C(CCC(N)=O)NC(=O)C(CCC(=O)O)NC(=O)C(Cc1ccc(O)cc1)NC(=O)C(NC(=O)C(CCCNC(=N)N)NC(=O)CNC(=O)CNC(=O)CNC(=O)C(NC(=O)C(NC(=O)C(CCSC)NC(=O)C(NC(=O)C(CCC(=O)O)NC(=O)C1CCCN1C(=O)C(NC(=O)C(CC(=O)O)NC(=O)CNC(=O)C(CS)NC(=O)C(C)NC(=O)C(C)NC(=O)C(NC(=O)C(C)NC(=O)C(CCC(=O)O)NC(=O)C(CC(=O)O)NC(=O)C(NC(=O)C(CO)NC(=O)C(C)NC(=O)C(NC(=O)C(Cc1c[nH]c2ccccc12)NC(=O)C(NC(=O)C(NC(=O)C(CCCNC(=N)N)NC(=O)C(CC(=O)O)NC(=O)C(CC(=O)O)NC(=O)C(C)NC(=O)CNC(=O)CNC(=O)C(CCC(N)=O)NC(=O)C(CO)NC(=O)C(CO)NC(=O)C(CC(C)C)NC(=O)C(NC(=O)C(NC(=O)C(CC(N)=O)NC(=O)C(CCCCN)NC(=O)C(CCCNC(=N)N)NC(=O)CNC(=O)C1CCCN1C(=O)C(CC(C)C)NC(=O)C1CCCN1C(=O)C(CCCNC(=N)N)NC(=O)CNC(=O)C(NC(=O)C(CO)NC(=O)C(CCC(=O)O)NC(=O)C(Cc1c[nH]c2ccccc12)NC(=O)C(NC(=O)C(Cc1cnc[nH]1)NC(=O)C(CCCNC(=N)N)NC(=O)CNC(=O)C(CCSC)NC(=O)C(NC(=O)C(NC(=O)C1CCCN1C(=O)C(CCCCN)NC(=O)C(CC(=O)O)NC(=O)C(CC(C)C)NC(=O)C(NC(=O)C(CC(N)=O)NC(=O)C(CCCNC(=N)N)NC(=O)C(CCCCN)NC(=O)C(Cc1ccccc1)NC(=O)C(Cc1c[nH]c2ccccc12)NC(=O)C(C)NC(=O)C(CC(C)C)NC(=O)C(CC(=O)O)NC(=O)C(C)NC(=O)C1CCCN1C(=O)C(CC(C)C)NC(=O)C(CC(N)=O)NC(=O)C(Cc1c[nH]c2ccccc12)NC(=O)C1CCCN1C(=O)C(CCSC)NC(=O)C(C)NC(=O)C(CC(N)=O)NC(=O)C(CCC(=O)O)NC(=O)C(CCSC)NC(=O)CNC(=O)C(NC(=O)C(NC(=O)C(CCCNC(=N)N)NC(=O)C(CC(=O)O)NC(=O)C(NC(=O)C(C)NC(=O)C(CC(C)C)NC(=O)C(C)NC(=O)C(C)NC(=O)C(NC(=O)C(CC(C)C)NC(=O)C(CO)NC(=O)C(NC(=O)C(N)CCSC)C(C)CC)C(C)CC)C(C)C)C(C)C)C(C)CC)C(C)O)C(C)C)C(C)CC)C(C)O)C(C)CC)C(C)CC)C(C)CC)C(C)C)C(C)O)C(C)C)C(C)C)C(C)CC)C(C)C)C(C)CC)C(C)C)C(C)CC)C(C)C)C(=O)NC(C)C(=O)NC(CCC(N)=O)C(=O)NC(CCCCN)C(=O)NC(CC(C)C)C(=O)NC(Cc1ccc(O)cc1)C(=O)NC(CC(C)C)C(=O)NC(C(=O)NC(Cc1cnc[nH]1)C(=O)NC(C(=O)NC(CC(=O)O)C(=O)NC(C)C(=O)NC(CCC(=O)O)C(=O)NC(C(=O)NC(CCC(=O)O)C(=O)NCC(=O)NC(CC(=O)O)C(=O)NC(C(=O)NC(Cc1cnc[nH]1)C(=O)NC(Cc1ccccc1)C(=O)N1CCCC1C(=O)NC(CC(=O)O)C(=O)NC(Cc1ccc(O)cc1)C(=O)NC(CC)C(=O)N1CCCC1C(=O)NC(C)C(=O)NC(CC(=O)O)C(=O)NC(Cc1c[nH]c2ccccc12)C(=O)NC(CCC(=O)O)C(=O)NC(CO)C(=O)NC(C(=O)NC(Cc1ccccc1)C(=O)NC(CO)C(=O)NC(CCC(=O)O)C(=O)NC(Cc1ccccc1)C(=O)NC(Cc1cnc[nH]1)C(=O)NC(CC(=O)O)C(=O)NC(C)C(=O)NC(CC(=O)O)C(=O)NC(C)C(=O)NC(CCC(N)=O)C(=O)NC(CC(N)=O)C(=O)NC(CO)C(=O)NC(Cc1cnc[nH]1)C(=O)NC(CO)C(=O)NC(Cc1ccc(O)cc1)C(=O)NC(CS)C(=O)NC(Cc1ccccc1)C(=O)NC(CCCCN)C(=O)NC(C(=O)NC(CC(C)C)C(=O)NC(CCC(=O)O)C(=O)NC(CCCNC(=N)N)C(=O)NC(CC)C(=O)O)C(C)CC)C(C)C)C(C)O)C(C)C)C(C)CC)C(C)O
3. Wait for it to appear

Actual behavior
The 3 dots loading indicator appears but not the structure.
It takes 40 seconds for the structure to appear on the canvas.

Expected behavior
Expecting the structure of the large molecule to appear in the ketcher editor

Ketcher version
Ketcher 2.15