feat(types): add WithTimestamps utility type

[baruchiro]

Summary

When working with TypeScript and Mongoose, it's useful to have a type that represents a document with timestamp fields. This is especially helpful when:

• Creating DTOs that will be stored with timestamps
• Working with document results from queries where timestamps are included

Examples

@Schema({
	timestamps: true,
})
class User {
	@Prop({ type: String, required: true })
	username: string;

	@Prop({ type: String, required: true })
	email: string;
}

export type UserDocument = WithId<WithTimestamp<User>>;

This utility type is inspired by the MongoDB driver's WithId<T> type and was originally discussed in a PR to the MongoDB driver repository: mongodb/node-mongodb-native#4462, before determining Mongoose was the more appropriate place for this functionality since Mongoose (not the driver) is responsible for managing timestamp fields.

[vkarpov15]

LGTM, this is excellent, thank you 👍