chore: update Angular and related dependencies to version 19.2.x

[akaustav]

Change Summary

This PR upgrades Angular core, CLI, Material, CDK, and related dependencies to meet the latest Angular 19 requirements.

Fixes #3

How

The following steps were taken to make the changes in this PR:

1. Created a new temporary Angular 19 project with @angular/animations and @angular/material using the following Angular CLI command:

   npx -p @angular/cli@19 ng new akaustav-angular-dark-mode --style=scss --routing=false
   npx -p @angular/cli@19 ng add @angular/animations
   npx -p @angular/cli@19 ng add @angular/material

2. Copied over appropriate lines from the package.json file of the newly created project to the existing project's package.json, specifically updating:

   • scripts
   • dependencies
   • devDependencies

3. The following unnecessary or deprecated packages were removed or replaced:

   "@angular/flex-layout": "^12.0.0-beta.34",
   "@types/jasmine": "~3.6.0",
   "@types/node": "^12.11.1",
   "codelyzer": "^6.0.0",
   "jasmine-spec-reporter": "~5.0.0",
   "karma-coverage-istanbul-reporter": "~3.0.2",
   "protractor": "~7.0.0",
   "ts-node": "~8.3.0",
   "tslint": "~6.1.0",

4. Removed the old package-lock.json file to ensure a clean installation of dependencies.

5. Installed the updated dependencies and generated a new package-lock.json file by running:

   npm install

6. Verified the application is working correctly with the new Angular version using:

   npm start

[akaustav]

@thisiszoaib - I have attempted a fix for issue #3 in this PR. For your consideration.