Rule location should contain the whole rule

[MatejKastak]

In order to keep consistency, rule location should encapsulate the whole rule (the string case is similar).

• rule.location.begin should be first character of the rule (can be even modifiers)
• rule.location.end should be the last character of the rule }
• rule.token_name can be exposed to provide access to the (probably) commonly accessed token the rule name

    def test_rule_location(self):
        ymod = yaramod.Yaramod()
        yara_file = ymod.parse_string(r'''rule rule1 : Tag1 {
    strings:
        $1 = "Hello World!"
    condition:
        false
}
''')
        r = yara_file.rules[0]
        self.assertEqual(r.location.begin.line, 1)
        self.assertEqual(r.location.begin.column, 1)
        self.assertEqual(r.location.end.line, 6)
        self.assertEqual(r.location.end.column, 1)