`INTERVAL '1 hour'` should be equivalent to `INTERVAL 1 HOUR`

**Use case**
People are used to Postgres.
{
    
    if (pos->type == TokenType::QuotedIdentifier)
    {
        ReadBufferFromMemory buf(pos->begin, pos->size());
        String s;
        if (*pos->begin == '`')
            readBackQuotedStringWithSQLStyle(s, buf);
        else
            readDoubleQuotedStringWithSQLStyle(s, buf);
        if (s.empty())    
            return false;
        node = std::make_shared<ASTIdentifier>(s);
        ++pos;
        return true;
    }
    else if (pos->type == TokenType::BareWord)
    {
        node = std::make_shared<ASTIdentifier>(String(pos->begin, pos->end));
        ++pos;
        return true;
    }
    return false;
}
bool ParserCompoundIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)