This commit removes the main MP2 migration class and its test class. It
also removes two SQL files that were used in the test class. One of
those files executed the following query:
`SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO"`
Removing this query made the tests inside SubscriberSegmentTest fail
when running the whole integration test suite. To work around this, I
added the above mentioned query to SubscriberSegmentTest. I'm not sure
why this test class fails without this query when running all the tests
but it doesn't when it is executed alone. Probably there is another test
class changing the SQL_MODE. Since SubscriberSegmentTest is a test class
for a Paris model that we will eventually remove, I decided it was not
necessary to investigate this further.
[MAILPOET-4376]
It was necessary to deprecate the filter
mailpoet_archive_email_subject and create a new one since the type
of one of the parameters passed to the filter had to change.
[MAILPOET-4307]
When the plugin is initially installed it may download translations from .org.
The translations from .org may have a newer date then translations from .com, but are incomplete.
This change ensures that translations installed from .org are always replaced by translations from .com.
[MAILPOET-4144]
- Based on how the NewsletterShortcodes service is implemented it's safer to instanciate
it inside the user method and not inject it in the class contructor
- Revert back the changes added to MailPoet\Newsletter\Shortcodes\Categories\Subscriber::process
[MAILPOET-4069]
