dropping all the unnecessary storing of separators

[Janther]

according to the documentation the separator will always be the same for each node.

/**
 * VersionExpressionSets       = (* item: *)  VersionExpressionSet       ((* separator: *) BAR_BAR (* item: *) VersionExpressionSet)*;
 * SimpleVersionLiteral        = (* item: *)  VERSION_SPECIFIER          ((* separator: *) PERIOD  (* item: *) VERSION_SPECIFIER)*;
 * ImportDeconstructionSymbols = (* item: *)  ImportDeconstructionSymbol ((* separator: *) COMMA   (* item: *) ImportDeconstructionSymbol)*;
 * UsingDeconstructionSymbols  = (* item: *)  UsingDeconstructionSymbol  ((* separator: *) COMMA   (* item: *) UsingDeconstructionSymbol)*;
 * InheritanceTypes            = (* item: *)  InheritanceType            ((* separator: *) COMMA   (* item: *) InheritanceType)*;
 * EnumMembers                 = ((* item: *) IDENTIFIER                 ((* separator: *) COMMA   (* item: *) IDENTIFIER)*)?;
 * Parameters                  = ((* item: *) Parameter                  ((* separator: *) COMMA   (* item: *) Parameter)*)?;
 * OverridePaths               = (* item: *)  IdentifierPath             ((* separator: *) COMMA   (* item: *) IdentifierPath)*;
 * EventParameters             = ((* item: *) EventParameter             ((* separator: *) COMMA   (* item: *) EventParameter)*)?;
 * ErrorParameters             = ((* item: *) ErrorParameter             ((* separator: *) COMMA   (* item: *) ErrorParameter)*)?;
 * AssemblyFlags               = (* item: *)  StringLiteral              ((* separator: *) COMMA   (* item: *) StringLiteral)*;
 * TupleDeconstructionElements = (* item: *)  TupleDeconstructionElement ((* separator: *) COMMA   (* item: *) TupleDeconstructionElement)*;
 * PositionalArguments         = ((* item: *) Expression                 ((* separator: *) COMMA   (* item: *) Expression)*)?;
 * NamedArguments              = ((* item: *) NamedArgument              ((* separator: *) COMMA   (* item: *) NamedArgument)*)?;
 * CallOptions                 = (* item: *)  NamedArgument              ((* separator: *) COMMA   (* item: *) NamedArgument)*;
 * TupleValues                 = (* item: *)  TupleValue                 ((* separator: *) COMMA   (* item: *) TupleValue)*;
 * ArrayValues                 = (* item: *)  Expression                 ((* separator: *) COMMA   (* item: *) Expression)*;
 * IdentifierPath              = (* item: *)  IDENTIFIER                 ((* separator: *) PERIOD  (* item: *) IDENTIFIER)*;
 * YulParameters               = ((* item: *) YUL_IDENTIFIER             ((* separator: *) COMMA   (* item: *) YUL_IDENTIFIER)*)?;
 * YulVariableNames            = (* item: *)  YUL_IDENTIFIER             ((* separator: *) COMMA   (* item: *) YUL_IDENTIFIER)*;
 * YulArguments                = ((* item: *) YulExpression              ((* separator: *) COMMA   (* item: *) YulExpression)*)?;
 * YulPaths                    = (* item: *)  YulPath                    ((* separator: *) COMMA   (* item: *) YulPath)*;
 * YulPath                     = (* item: *)  YUL_IDENTIFIER             ((* separator: *) PERIOD  (* item: *) YUL_IDENTIFIER)*;
 */

If in the future there is a separator added that could have different representations according to the situation, we can add logic just for that.