Molecular mass and Molecular formula are not calculated for Molecule (custom CHEM)

**Steps to Reproduce**
1. Go to Macromolecules mode - Flex canvas (empty)
2. Load from HELM: `CHEM1{[[H]([*:1])[He]1[Li][Be]2[K]3[Ca]4[Sc]5C([B]2)[N]O2[V]6[Ti]5[Rb]5[Kr]7[Br]4[SeH]4[In]8[Cd]9[Ag]%10[Pd]%11[Os]%12[Re]([W][Ru][Rh]%11[Zn][Ga]%11S([PH])[Cl]1[Ar]3[AsH]4[Ge]%10%11)[Db][Sg]1[Bh]3[Hs]4[Pm]%10[Nd]%11[Pr]1[Ce]([La])[Th][Pa][U]%11[Np][Pu]1[Am][Cm]%11[Gd]%13[Eu]([Sm]%101)[Ds]1[Mt]4[Au]([Pt]9[Ir]%123)[Hg]3[Tl]4[PbH]9[BiH]%10[PoH]%12[Xe]%14[I]([TeH]9[SbH]7[SnH]83)[Sr]5[Y]3[Cr]6[Mn]5[Ne](F2)[Na][Mg]2[Co]6[Fe]5[Nb]5[Zr]3[Cs]%14[Ba]3[Rn]7[At]%12[Mc]8[Fl]9[Nh]%10[Cn]([Tb]%13[Dy]%10[Ho]9[Er]9[Tm]%12[Yb]([No]([Md][Fm]9[Es][Cf]%10[Bk]%11)[Lr])[Lu]([Ac])[Og][Ts]([Fr]7[Ra]([Rf])[Ta][Hf]3[Mo]5[Tc][Ni]6[Cu][Si][Al]2)[Lv]%128)[Rg]41 |^3:8,34,115,^1:9,10,16,18,28,30,31,33,60,62,65,67,84,116,$;_R1;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;$|]}$$$$V2.0`
3. Open Calculate properties (press `Alt+C`)

**Actual behavior**
Calculate properties window is empty

**Expected behavior**
Molecular mass and Molecular formula values are shown on the Calculate properties window

**Environment details:**
- Ketcher Version 3.4.0-rc.3 Build at 2025-05-15; 19:51:50
- Indigo Version 1.32.0-rc.2.0-g94ab270bd-wasm32-wasm-clang-19.0.0
- Chrome Version 136.0.7103.93 (Official Build) (64-bit)
- Win10

Found while testing: https://github.com/epam/Indigo/issues/2552