Refactoring of roles and notifications about antagonist assignment (#16864)

* Refactoring of antagonist roles and notifications about antagonist role assignment.
Refactoring of traitor assignment methods and bug fixing.

* Announcement files moved, code is adjusted to new revision

* Play to entity changed to play to global cause of mono audio restrictions.

* Path to audio files changed to sound specifiers, unique alerts for each role.

* Uncommited changes

* New alert sounds for each antag role.

* PR review fixes

* Antagonist role assignment sound notifications moved to Systems, sounds moved to Components.

* License update

* Fixed naming and redundant parameters

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Co-authored-by: Титов Вячеслав Витальевич <rincew1nd@yandex.ru>

Content.Server/Objectives/Requirements/TraitorRequirement.cs

@@ -1,6 +1,8 @@
 using Content.Server.Objectives.Interfaces;
+using Content.Server.Roles;
 using Content.Server.Traitor;
 using JetBrains.Annotations;
+using TraitorRole = Content.Server.Roles.TraitorRole;
 
 namespace Content.Server.Objectives.Requirements
 {