Removed NioTSO client and server

- NioTSO client isn't needed because we're using RayLib
- Added FreeSO's API server to handle most backend operations

server/FSO.Server.Database/DatabaseScripts/changes/0017_inbox_events.sql

@@ -0,0 +1,50 @@
+CREATE TABLE `fso_inbox` (
+  `message_id` INT NOT NULL AUTO_INCREMENT,
+  `sender_id` INT UNSIGNED NOT NULL,
+  `target_id` INT UNSIGNED NOT NULL,
+  `subject` VARCHAR(128) NOT NULL,
+  `body` VARCHAR(1500) NOT NULL,
+  `sender_name` VARCHAR(64) NOT NULL,
+  `time` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  `msg_type` INT NOT NULL DEFAULT 0,
+  `msg_subtype` INT NOT NULL DEFAULT 0,
+  `read_state` INT NOT NULL DEFAULT 0,
+  `reply_id` INT NULL DEFAULT NULL,
+  PRIMARY KEY (`message_id`),
+  INDEX `index_target_inbox` (`target_id` ASC),
+  CONSTRAINT `fso_target_avatar`
+    FOREIGN KEY (`target_id`)
+    REFERENCES `fso_avatars` (`avatar_id`)
+    ON DELETE CASCADE
+    ON UPDATE CASCADE);
+
+CREATE TABLE `fso_events` (
+  `event_id` INT NOT NULL AUTO_INCREMENT,
+  `title` VARCHAR(128) NULL,
+  `description` VARCHAR(500) NULL,
+  `start_day` DATETIME NOT NULL,
+  `end_day` DATETIME NOT NULL,
+  `type` ENUM('mail_only', 'free_object', 'free_money', 'free_green', 'obj_tuning') NOT NULL,
+  `value` INT NOT NULL,
+  `value2` INT NOT NULL DEFAULT 0,
+  `mail_subject` VARCHAR(128) NULL,
+  `mail_message` VARCHAR(1000) NULL,
+  `mail_sender` INT NULL,
+  `mail_sender_name` VARCHAR(64) NULL,
+  PRIMARY KEY (`event_id`));
+
+CREATE TABLE `fso_event_participation` (
+  `event_id` INT NOT NULL,
+  `user_id` INT UNSIGNED NOT NULL,
+  PRIMARY KEY (`event_id`, `user_id`),
+  INDEX `fso_event_part_user_idx` (`user_id` ASC),
+  CONSTRAINT `fso_event_part_id`
+    FOREIGN KEY (`event_id`)
+    REFERENCES `fso_events` (`event_id`)
+    ON DELETE CASCADE
+    ON UPDATE NO ACTION,
+  CONSTRAINT `fso_event_part_user`
+    FOREIGN KEY (`user_id`)
+    REFERENCES `fso_users` (`user_id`)
+    ON DELETE CASCADE
+    ON UPDATE CASCADE);