Add AFIRMA indicator implementation with validation tests and documentation

- Implemented AFIRMA (Autoregressive Finite Impulse Response Moving Average) class with support for various window types and batch processing.
- Created unit tests for AFIRMA to validate internal consistency, streaming, and batch processing.
- Added comprehensive documentation for AFIRMA, including usage examples, performance profile, and parameter selection guide.
- Removed obsolete omnisharp.json configuration file.

.vscode/settings.json

@@ -150,7 +150,7 @@
 
   "dotnet.defaultSolution": "QuanTAlib.sln",
   "dotnet.testController.enabled": true,
-  "dotnet.unitTests.runSettingsPath": "coverage.runsettings",
+  "dotnet.unitTests.runSettingsPath": ".config/coverage.runsettings",
   "dotnet.completion.showCompletionItemsFromUnimportedNamespaces": true,
   "dotnet.server.useOmnisharp": false,
 
@@ -178,4 +178,4 @@
   // ? Run tests after accepting: dotnet test
   // ? Check performance impact with benchmarks
   // ? Validate against reference implementations
-}
+}