Missing words and letters in the info message for the Active Directory Application, OnlyOffice Connector Application, FAQ Application and Flash Messages Application in Extension Manager

Steps to reproduce:

1. Click on Administer Wiki
2. Click on Add Extensions from Extension Manager
3. Observe the info messages of the recommended extensions

Expected results: For Active Directory Application and OnlyOffice Connector Application - "Note that this is a paying application"
The FAQ Application message should be "Questions and answers for frequently asked questions"
Flash Messages Application - "Allows you to create Flash messages aiming at one or multiple local groups"

Actual results: The info messages for Active Directory Application and OnlyOffice Connector Application are missing "is" - "Note that this a paying application."
The FAQ Application info message is missing an "s" to "answer"
Flash Messages Application info message is missing an "s" to "Allow"