Remove OracleDatabaseTasks was deprecated, because this was provided by 3rd-party.
Remove SqlseverDatabaseTasks was deprecated, because this was provided by 3rd-party.
Remove FirebirdDatabaseTasks was deprecated, because this was provided by 3rd-party.
Merge pull request #10853 from kennyj/deprecated-database_tasks

Remove Oracle / Sqlserver / Firebird database tasks were deprecated since 4.0.