types(document): make sure toObject() and toJSON() apply versionKey __v

[vkarpov15]

Fix #15077

Summary

#15077 points out that lean() and toObject() should return compatible types, but currently do not due to __v

Examples

[hasezoey]

LGTM, though cases some expected type test failures in typegoose.
Maybe consider putting this into the next minor version.

The errors for context

fail ./test/tests/types/basicTypegoose.test-d.ts

Error: Type 'SomeClass & { _id: ObjectId; } & { __v: number; }' is not identical to type 'SomeClass & { _id: ObjectId; } & Required<{ _id: ObjectId; }>'.

  275 | 
  276 |   expect(toobj).type.toBe<
  277 |     SomeClass & { _id: typegoose.mongoose.Types.ObjectId } & Required<{
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  278 |         _id: typegoose.mongoose.Types.ObjectId;
      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  279 |       }>
      | ~~~~~~~~
  280 |   >();

        at ./test/tests/types/basicTypegoose.test-d.ts:277:5

Error: Type 'FlattenMaps<SomeClass & { _id: ObjectId; } & { __v: number; }>' is not identical to type 'FlattenMaps<SomeClass & { _id: ObjectId; }>'.

  279 |       }>
  280 |   >();
  281 |   expect(tojson).type.toBe<typegoose.mongoose.FlattenMaps<SomeClass & { _id: typegoose.mongoose.Types.ObjectId }>>();
      |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  282 | }
  283 | 
  284 | gh732();

        at ./test/tests/types/basicTypegoose.test-d.ts:281:28

[vkarpov15]

Merging into 8.10 branch.