Add typehints in favour of PHPDocs for TransformsRequest middleware

[DannyvdSluijs]

As a minor improvement (and since the project is only targeting >= PHP 7.1) I've updated the TransformsRequest middleware to use the type hints where possible and removing the (redundant) @params and @return.
This PR doesn't touch the cleanValue method as it is overloaded and contains support for mixed types.

Feel free to reply if this PR needs rework (Since this is my 1st PR on this project)

[devcircus]

The framework doesn't use return typehints at this time. Doc blocks are preferred. While this may change in the future, this file should be consistent with the rest of the framework.

[driesvints]

Heya, thanks for sending in your first PR. Please see the comment above. At the moment we don't implement these type-hints in the framework.

[DannyvdSluijs]

Thnx for the feedback. However Im trying to wrap my head around why not to add these basic typehints (Especially the object type hints have been there since PHP 5, July 2004). Also reading laravel/ideas#1409 where the majority seems to be on the pro side. But there seems to be little progress on a feature which I consider very positive for strengthening the framework and assist the programmer. As currently the responsibility lies with the programmer using the framework. I would expect the framework to help.

Btw there seems to be some typehints in the framework: https://github.com/laravel/framework/blob/5.8/src/Illuminate/Foundation/Testing/Concerns/MakesHttpRequests.php#L55

[mfn]

why not

I think these two things are relevant:

• As the answer given in here ( Add typehints in favour of PHPDocs for TransformsRequest middleware #28373 (comment) )

  this file should be consistent with the rest of the framework

• approval by Taylor Otwell

Basically Taylor so far hasn't gone forward merging such PRs which shows his stance is (not yet?) "pro" them.