refactor(dependency): migrate deepmerge to ts-deepmerge

[Neizan93]

Migrated the deepmerge library to ts-deepmerge for better TypeScript compatibility and enhanced type checking.

fixes #229

Summary

This PR migrates from the deepmerge library to ts-deepmerge, addressing an optimization warning in Angular 14 and later versions.

PR Checklist

Please check if your PR fulfills the following requirements:

• [X] The commit message follows our guidelines:
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [X] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Documentation content changes
• [ ] Other... Please describe:

Current Behavior

When integrating ngrx-store-localstorage with Angular 14 and later versions, a warning related to the deepmerge dependency emerges due to its CommonJS or AMD nature. This warning indicates potential optimization bailouts.

Issue Number: #229

New Behavior

The ngrx-store-localstorage library no longer relies on deepmerge. Instead, it uses ts-deepmerge, eliminating the aforementioned Angular warning and ensuring better type safety.

Breaking Change?

• [ ] Yes
• [X] No

Other information

This change not only resolves the current issue but also aligns the library closer to modern JS standards, making it more future-proof.