refactor: use ::class to config() param

[kenjis]

Description
::class keyword is better than string for IDE or static analysis.

Checklist:

• Securely signed commits
• [] Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• [] User guide updated
• Conforms to style guide

[TimexPeachtree]

Code looks great for refactor more concise.
want to check if this has going to be in a major update 4.4.x or within 4.3.x

[kenjis]

develop means 4.3.x now.

[mostafakhudair]

Why should the framework care about the IDE?
::class means more code line.

[datamweb]

Why should the framework care about the IDE?

Because it guides the developers. and provides more details when programming.

[kenjis]

1. If we use ::class, IDE can navigate us to the Config property.
   

2. When we use ::class, IDE can autocomplete the classname.
   

[kenjis]

::class means more code line.

If you mean use statements like use Config\Exceptions;,
I think it is better to write all use statements for all dependencies.
Then all classes on which this class depends will be visible.
Too many usesstatements mean too many dependencies, which may be an issue in class design.

config('classname') hides the dependency.

And if you use IDE, the use statement will be added automatically.