[8.0] Port the module 'account_move_template' to the new API

This PR contains the module ***account_move_template*** ported to the new API.
Test and installation seems to me ok.

Let's see what will be the TravisCI response and your reviews :wink: 
With `@api.multi`, self is already a browse record(set) of template_id so you don't need to have the `template_id` argument and browse it. Example:

```
@api.multi
def _get_template_line(self, line_number):
    lines = {}
    for line in self.template_line_ids:
        lines[line.sequence] = None
    return lines
```