Add translation string for mautic.campaign.twitter.tweet

[dongilbert]

Q	A
Bug fix?	Y
New feature?	N
Related user documentation PR URL	N/A
Related developer documentation PR URL	N/A
Issues addressed (#s or URLs)	N/A
BC breaks?	N/A
Deprecations?	N/A

Description:

Adds a translation string for the mautic.campaign.twitter.tweet translation key.

Steps to test this PR:

1. Apply the PR
2. Repeat the steps to reproduce the bug. You'll see that the string is translated.

Steps to reproduce the bug:

1. Create a campaign
2. Add a "Tweet contact" action and save the campaign
3. In the lower section of the campaign details on the "Actions" tab, you'll see a "Tweet contact" row. To the right on that row you'll see the string with a missing translation.

[mqueme]

??