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

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• [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)
• 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
• 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.