V14: Migrate notify action from char to string

[nikolajlauridsen]

Migrates the umbracoUser2NodeNotify.action column use the new action strings instead of the action letters. This involves changing the column type to Nvarchar(255), and mapping the action letters to the new action strings.

Additionally this also migrates the umbracoUserGroup2Permission.permission column to use Nvarchar(255), partly just to align the two, since it's referencing the same thing, but this will also allow for a compound key in the future.

Testing

On both Sqlite and MSSQL:

0. Ensure SMTP is configured
1. Create some content in v13
2. Enable notifications for the content
3. Migrate the database to v14.
4. The values in the mentioned tables should now be updated (except for 'H', since that's a deploy thing)
5. Content notifications should now work

[bergmania]

Looks good and tests good