Refactor logging level handling and remove example usage

* Updated `CommandLineOptions` and `ConfigurationObject` to use `LoggingLevel` type instead of string for log levels.
* Modified `LoggerFactory` to set logging levels using the new `LoggingLevelMapping` methods.
* Removed the `example-usage.ts` file as it was no longer needed.
* Adjusted `Threshold` class to simplify logging level management.

test/logger/Threshold.ts

@@ -1,4 +1,4 @@
-import {LoggingLevel, LoggingLevelMapping, type LoggingLevelType} from './LoggingLevel';
+import {LoggingLevel} from './LoggingLevel';
 
 export class Threshold {
   private readonly _level: {value: LoggingLevel};