feat: remove data annotation from entities

[Bulent Baris Kilic]

For #1

See the following link:

• Remove Data annotation
• Add ToString annotation.
• EqualsAndHashCode also can cause performance issues.
• According to the JPA specification, all entity classes are required to have a public or protected no-argument constructor.

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• remove @Data annotation
• remove @EqualsAndHashCode annotation
• add @ToString(onlyExplicitlyIncluded = true) to entity classes
• add not only @AllArgsConstructor annotation but also @NoArgsConstructor annotation to entity classes