[BUG] Body Validation not working as expected
### Describe the bug

I'm currently migrating a express application to Ts.ED. I used joi for the validation before and currently try to make AJV work, as i like the direct support & swagger integration.

I have a problem making the following work:

```ts
import { Integer, Required } from '@tsed/schema';

export class Test {
  @Integer()
  @Required()
  value: number;
}
```

```ts
@Post('/some-url')
async someFunction(@BodyParams() body: Test) {
  ...
}
```

Also writing `@BodyParams(Test) ...` does not work.

I don't find an exact documentation for this, except from `Any model used on parameter and annotated with one of JsonSchema decorator will be validated with AJV.` [written here](https://tsed.io/docs/validation.html). So i guess my usage is correct and should work?

Also in my `server.ts` i have:

```ts
import '@tsed/ajv';
```

What does work for me is something like:
```ts
@Post('/some-url')
async someFunction(@BodyParams('value') @Integer() @Required value: number) {
  ...
}
```
but i would like to validate the whole body. Is this possible?

### To Reproduce

Should be quite is to set up, see above.

Because this is also a kind of "should this be even possible" - issue, i dind't create an extra reproducable repo. If you need one, let me know.

### Expected behavior

I would expect the full body to be validated correctly when used as described above. The request should ail with the ajv error.

### Code snippets

_No response_

### Repository URL example

_No response_

### OS

macOS

### Node version

18.17.1

### Library version

7.41.2

### Additional context

_No response_