forwarding variable smiles to get_expanded_groups to avoid "variable not found error"

[thomvet]

Running:
f = get_groups_from_smiles("C1OCOCO1", UNIFACGroups) #1,3,5-trioxane

Results in:

ERROR: UndefVarError: `smiles` not defined
Stacktrace:
 [1] get_expanded_groups(mol::MolecularGraph.SMILESMolGraph, groups::Vector{GCPair}, atoms::UnitRange{Int64}, __bonds::Vector{Tuple{Int64, Int64}}, check::Bool)
   @ GCIdentifier C:\Users\thvt\.julia\packages\GCIdentifier\zQuz2\src\group_search.jl:258
 [2] _get_groups_from_smiles(smiles::String, groups::Vector{GCPair}, connectivity::Bool, check::Bool)
   @ GCIdentifier C:\Users\thvt\.julia\packages\GCIdentifier\zQuz2\src\group_search.jl:146
 [3] get_groups_from_smiles(smiles::String, groups::Vector{GCPair}; connectivity::Bool, check::Bool)
   @ GCIdentifier C:\Users\thvt\.julia\packages\GCIdentifier\zQuz2\src\group_search.jl:112
 [4] get_groups_from_smiles(smiles::String, groups::Vector{GCPair})
   @ GCIdentifier C:\Users\thvt\.julia\packages\GCIdentifier\zQuz2\src\group_search.jl:110
 [5] top-level scope
   @ REPL[163]:1

Because the variable smiles is not passed on to get_expanded_groups(), but the function tries to raise an error that accesses this variable.

This small PR fixes the issue in the simplest possible way, i.e., by adding the variable smiles as an argument to the get_expanded_groups() function.

[longemen3000]

Great!