add group moderation and banning functionality to api (#13)

* add group moderation and banning functionality to api

* set moderator to false on group migration

* send IsModerator in addition on group join

Co-authored-by: rootdarkarchon <root.darkarchon@outlook.com>

MareSynchronosServer/MareSynchronosShared/Migrations/20221006115929_GroupModerator.cs

@@ -0,0 +1,26 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace MareSynchronosServer.Migrations
+{
+    public partial class GroupModerator : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "is_moderator",
+                table: "group_pairs",
+                type: "boolean",
+                nullable: false,
+                defaultValue: false);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "is_moderator",
+                table: "group_pairs");
+        }
+    }
+}