Adds several core models needed for functionality

This commit includes the following models:
- Guest
- Reservation
- Room
- Transaction

The guest model is used to represent a guest which will create a unique
guest entry represented through its ID. The model also collects
represents and reflects a guests first and last name and their personal
information including email and credit card, phone number still needs to
be included.

The reservation model focuses on #9. See the issue for more specific
details. The changes made to better define this model include changing
the original Cancellation variable to a more meaningful one called
Status. The Status variable can either be Active, Changed, or Cancelled
and enums are used as a better approach than creating and setting an int
value for an int variable. The same approach was used for the
reservation types. Furthermore, the original model was missing the
StartDate and EndDate, confusing them for the CheckIn and CheckOut date,
which can, but is not guaranteed to be identical. NoShow was moved from
the transaction model to the reservation model because it made more
sense.

The Transaction and Room models are currently empty and were created in
preperation of work. Transaction, formerly Payments, did have a model
built, however git stash did not properly store these changes.

Additional changes include the beginning of working on the main
Program.cs, however, this was mostly to ensure that the console was
outputting and the project was building.

Other (less important) notes...
A .gitignore has been added for C#, this is modified to include .vs
files since they are mostly cache files. If this breaks the project it
can always be dropped later.

The project file itself has been versioned, it may not play nice on
other machines, but ideally should be fine and nothing should go wrong
when running the project file.

OpheliasOasis/Models/Guest.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Ophelias.Guest.Models
+{
+    internal class Guest
+    {
+        internal int Id;
+        internal string FirstName;
+        internal string LastName;
+        internal string Email;
+        internal string? CreditCard;
+
+        internal Guest(int id, string fname, string lname, string email)
+        {
+            Id = id;
+            FirstName = fname;
+            LastName = lname;
+            Email = email;
+        }
+        internal Guest(int id, string fname, string lname, string email, string cc)
+        {
+            Id = id;
+            FirstName = fname;
+            LastName = lname;
+            Email = email;
+            CreditCard = cc;
+        }
+
+    }
+}