ref #9436
Currently EPHEMERAL column requires an explicit default value provided on CREATE TABLE - we can allow implicit default there

ParserStringLiteral string_literal_parser;
    ParserCodec codec_parser;
    ParserExpression expression_parser;
    
    ASTPtr name;
    if (!name_parser.parse(pos, name, expected))
        return false;
    const auto column_declaration = std::make_shared<ASTColumnDeclaration>();
    tryGetIdentifierNameInto(name, column_declaration->name);
    
    
    
    
    
    
    if (!require_type && s_remove.checkWithoutMoving(pos, expected))
    {
        if (!check_keywords_after_name)
            return false;
        node = column_declaration;
        return true;
    }
    /** column name should be followed by type name if it
      *    is not immediately followed by {DEFAULT, MATERIALIZED, ALIAS, COMMENT}
      */
    ASTPtr type;
    String default_specifier;
    std::optional<bool> null_modifier;
    ASTPtr default_expression;
    ASTPtr comment_expression;