[CLASS_TRANSFORMERS] Extends class-transform package with EnumFallback decorator

[amarlankri]

Description

Create class-transformers package with new decorator EnumFallback. This decorator can be used as follows:

import { EnumFallback } from '@algoan/nestjs-class-transformers';

export enum UserRole {
  ADMIN = 'ADMIN',
  READER = 'READER',
}

class User {
  @EnumFallback({
    type: UserRole,
    fallback: (value: UserRole) => UserRole.READER // if the role is not "ADMIN" or "READER", then the role will be "READER".
  })
  public role?: UserRole;
}

Finishes implementation started in #836

Motivation and Context

Fix #834

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[qhdinh]

If there is error in the fallback function, you think we should throw error or return a specific value?

[amarlankri]

I don't think so 🤔 Unlike the logging feature, this decorator may have a real impact on the application behaviour. In my opinion, it is more like the function you pass to Array.map for instance. It means that if the given function fails, it is not the responsibility to the library to handle it.

What do you think?

[qhdinh]

Okay, so let the client handle it himself.

[qhdinh]

Could you please add a test when the fallback function is more than just returning a value? e.g. verifying a logging as we discussed