In future changes, services will be able to control whether their text
messages will be prefixed with the name of their service.
This commit:
- adds a column to store the value of that setting
- makes the service model take notice of it, if it were to have a value
set
It doesn’t:
- provide a way of setting the value of this column
Currently the column can have three values:
- `None` – ignore it (this is what all current services will start as)
and continue to determine whether to prefix messages by looking at the
sender
- `True` – always the service name to the start of text messages
- `False` – never add the service name to the start of text messages
In the future we’ll migrate all services to be either `True` or `False`,
the `None` will go away and all services will have direct control over
the setting.
