feat(config): add DexJobOptions configuration system and update placeholder pattern

- Add SectionName constant to DexJobOptions
- Update placeholder pattern to {#INT#BATCH_ID}
- Add DexJob configuration section to appsettings.json
- Add IConfiguration parameter to DependencyInjection for options binding
- Add Microsoft.Extensions.Options.ConfigurationExtensions package for .NET Framework 4.8
- Improve code documentation and move class into namespace

ECMJobRunner.WebCron/appsettings.json

@@ -23,5 +23,28 @@
   },
   "ProfileWorker": {
     "IntervalMS": 60000
+  },
+  "DexJob": {
+    "Error": {
+      "MainQuery": {
+        "OnExecution": "Stop",
+        "IfNullOrWhiteSpace": "Ignore",
+        "OnUnexpectedResult": "Stop"
+      },
+      "CheckQuery": {
+        "OnExecution": "Stop",
+        "IfNullOrWhiteSpace": "Ignore",
+        "OnUnexpectedResult": "Stop"
+      },
+      "ReCRequest": {
+        "OnSending": "Stop"
+      }
+    },
+    "Placeholders": {
+      "BatchId": {
+        "Pattern": "{#INT#BATCH_ID}",
+        "RegexOptions": "IgnoreCase"
+      }
+    }
   }
 }