[9.x] Stringables for Translator class

[peterfox]

Changes

• Adds a stringable method to the Translator class
• Adds the ReflectsClosures trait to the Translator class
• Adds a mechanism to process objects passed into the translator get method to return the object into a string.
• Adds a test to demo the use of altering how a Carbon datetime object could be altered from its default string form.

Why

This behaves precisely to how Stringables work with the Blade compiler. The use case for this is that sometimes it's a pain having to format everything before passing it to the get method. Instead, the translator can handle the values as objects and convert them to strings.

Notes

This won't cause conflicts or break anything, as it's all additional code. That said, there is no Facade for the Translator currently. This would be hard to document as a feature as the more visible method would be:

trans()->stringable(fn(Carbon $carbon) => $carbon->format('Y-m-d'));