Reorganize all observatory core projects into monorepo (#25)

* chore: move all observatory repos to core

* only save journal folder on change, don't constantly re-check during monitoring

* chore: monorepo project changes

* chore: monorepo migration

ObservatoryFramework/Files/Journal/JournalBase.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace Observatory.Framework.Files.Journal
+{
+    public class JournalBase
+    {
+        [JsonPropertyName("timestamp")]
+        public string Timestamp { get; init; }
+
+        [JsonIgnore]
+        public DateTime TimestampDateTime
+        {
+            get
+            {
+                return DateTime.ParseExact(Timestamp, "yyyy-MM-ddTHH:mm:ssZ", null, System.Globalization.DateTimeStyles.AssumeUniversal);
+            }
+        }
+
+        [JsonPropertyName("event")]
+        public string Event { get;  init; }
+
+        [JsonExtensionData]
+        public Dictionary<string, object> AdditionalProperties { get; init; }
+
+        [JsonIgnore]
+        public string Json 
+        {
+            get => json; 
+            set
+            {
+                if (json == null || string.IsNullOrWhiteSpace(json))
+                {
+                    json = value;
+                }
+                else
+                {
+                    throw new Exception("Journal property \"Json\" can only be set while empty.");
+                }
+            }
+        }
+
+        private string json;
+
+    }
+}