Refactor to add readonly interfaces

Using more granular interfaces adds to expressiveness of the code.
Knowing what needs to mutate the state explicitly helps easier
understanding of the code and therefore increases the maintainability.

src/application/Context/State/Code/ApplicationCode.ts

@@ -2,7 +2,7 @@ import { CodeChangedEvent } from './Event/CodeChangedEvent';
 import { CodePosition } from './Position/CodePosition';
 import { ICodeChangedEvent } from './Event/ICodeChangedEvent';
 import { SelectedScript } from '@/application/Context/State/Selection/SelectedScript';
-import { IUserSelection } from '@/application/Context/State/Selection/IUserSelection';
+import { IReadOnlyUserSelection } from '@/application/Context/State/Selection/IUserSelection';
 import { UserScriptGenerator } from './Generation/UserScriptGenerator';
 import { EventSource } from '@/infrastructure/Events/EventSource';
 import { IApplicationCode } from './IApplicationCode';
@@ -16,7 +16,7 @@ export class ApplicationCode implements IApplicationCode {
     private scriptPositions = new Map<SelectedScript, CodePosition>();
 
     constructor(
-        userSelection: IUserSelection,
+        userSelection: IReadOnlyUserSelection,
         private readonly scriptingDefinition: IScriptingDefinition,
         private readonly generator: IUserScriptGenerator = new UserScriptGenerator()) {
         if (!userSelection) { throw new Error('userSelection is null or undefined'); }