### Summary

`ansible.template.is_template` tries to loop until it determines if the value is indeed a template.  Which means we could loop extremely large strings, that don't even remotely look like templates, before we bail.

However, we could benefit from moving `Templar.is_possibly_template` to the global scope, and testing whether the value after `jinja_env.preprocess` is even possibly a template, before doing more computationally complex validation.

### Issue Type

Feature Idea

### Component Name

lib/ansible/template/__init__.py

### Additional Information

<!--- Paste example playbooks or commands between quotes below -->
```yaml (paste below)

```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
The string inside of the {{ gets interpreted multiple times First by yaml.
    Then by python.  And finally by jinja2 as part of it's variable.  Because
    it is processed by both python and jinja2, the backslash escaped
    characters get unescaped twice.  This means that we'd normally have to use
    four backslashes to escape that.  This is painful for playbook authors as
    they have to remember different rules for inside vs outside of a jinja2
    expression (The backslashes outside of the "{{ }}" only get processed by
    yaml and python.  So they only need to be escaped once).  The following
    code fixes this by automatically performing the extra quoting of
    backslashes inside of a jinja2 expression.
    """
    if '\\' in data and '{{' in data:
        new_data = []
        d2 = jinja_env.preprocess(data)
        in_var = False
        for token in jinja_env.lex(d2):
            if token[1] == 'variable_begin':
                in_var = True
                new_data.append(token[2])
            elif token[1] == 'variable_end':
                in_var = False
                new_data.append(token[2])
            elif in_var and token[1] == 'string':
                
                new_data.append(token[2].replace('\\', '\\\\'))
            else:
                new_data.append(token[2])
        data = ''.join(new_data)
    return data
def is_template(data, jinja_env):