Added preferences backend (#465)

* Added preferences backend

* Gender -> Sex

* ClientPreferencesManager properties

* Username validation

* Fixed client init

* WIP db

* Actually working sqlite db

* Dropped shitty sqlite libraries, dropped DbUp, added MigrationManager

* Added profile deletion, test

* Docs, sanity, tests, cleanup

* Cleaned up profile and appearance, fixed running on .net core

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>

Content.Shared/Preferences/HumanoidCharacterProfile.cs

@@ -0,0 +1,36 @@
+using System;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Preferences
+{
+    [Serializable, NetSerializable]
+    public class HumanoidCharacterProfile : ICharacterProfile
+    {
+        public static HumanoidCharacterProfile Default()
+        {
+            return new HumanoidCharacterProfile
+            {
+                Name = "John Doe",
+                Age = 18,
+                Sex = Sex.Male,
+                CharacterAppearance = HumanoidCharacterAppearance.Default()
+            };
+        }
+
+        public string Name { get; set; }
+        public int Age { get; set; }
+        public Sex Sex { get; set; }
+        public ICharacterAppearance CharacterAppearance { get; set; }
+
+        public bool MemberwiseEquals(ICharacterProfile maybeOther)
+        {
+            if (!(maybeOther is HumanoidCharacterProfile other)) return false;
+            if (Name != other.Name) return false;
+            if (Age != other.Age) return false;
+            if (Sex != other.Sex) return false;
+            if (CharacterAppearance is null)
+                return other.CharacterAppearance is null;
+            return CharacterAppearance.MemberwiseEquals(other.CharacterAppearance);
+        }
+    }
+}