Refactor DI container for better structure and clarity

- Moved `TSinjex` class to `classes` directory for better organization.
- Updated imports across the codebase to reflect the new location of `TSinjex`.
- Introduced `Identifier` type to standardize dependency identifiers.
- Enhanced JSDoc comments for improved clarity and consistency.
- Adjusted error messages for `DependencyResolutionError` to provide clearer information.
- Updated and expanded decorator and function types to use `Identifier` type.

src/types/GenericContructor.ts

@@ -1,5 +1,6 @@
 /**
  * Generic constructor type.
+ * This type is used to define a constructor of a class.
  */
 export type GenericConstructor<
     T extends abstract new (...args: unknown[]) => InstanceType<T>,
@@ -7,6 +8,6 @@ export type GenericConstructor<
 
 /**
  * Force generic constructor type.
- * This type is used to force a class to be a constructor.
+ * This type is used to force a class to has a constructor.
  */
 export type ForceConstructor<T> = new (...args: unknown[]) => T;

src/types/Identifier.ts

@@ -0,0 +1,11 @@
+/**
+ * The dependency identifier.
+ * You can use any string as identifier.
+ * To create order, it is also possible to
+ * provide these with a separator: `GroupA.ClassZ`.
+ * The convection for naming is as follows:
+ * The name should generally correspond to the interface that is relevant.
+ * I.e. a class `ClassA` that implements the interface `IClassA` and is
+ * registered as a dependent class is registered under the interface name `IClassA`.
+ */
+export type Identifier = string;