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.Server/Preferences/Migrations/000_Initial.sql

@@ -0,0 +1,20 @@
+CREATE TABLE IF NOT EXISTS "HumanoidCharacterProfiles" (
+	"Id"	INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
+	"Player"	INTEGER NOT NULL,
+	"Slot"	INTEGER NOT NULL,
+	"Name"	TEXT NOT NULL,
+	"Age"	INTEGER NOT NULL,
+	"Sex"	TEXT NOT NULL,
+	"HairStyleName"	TEXT NOT NULL,
+	"HairColor"	TEXT NOT NULL,
+	"FacialHairStyleName"	TEXT NOT NULL,
+	"FacialHairColor"	TEXT NOT NULL,
+	"EyeColor"	TEXT NOT NULL,
+	"SkinColor"	TEXT NOT NULL,
+	FOREIGN KEY("Player") REFERENCES "PlayerPreferences"("Id")
+);
+CREATE TABLE IF NOT EXISTS "PlayerPreferences" (
+	"Id"	INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
+	"Username"	TEXT NOT NULL UNIQUE,
+	"SelectedCharacterIndex"	INTEGER NOT NULL
+);