[Admin] Improve breadcrumbs (especially for ProductVariants and PromotionCoupons)

[CoderMaggie]

Q	A
Branch?	1.4
Bug fix?	no
New feature?	rather an improvement
BC breaks?	no
Deprecations?	no
Related tickets	triggered by #10509 😄
License	MIT

The clue is to use entities names instead of codes, wherever it is possible. especially in entities that are under other entities like coupons or variants.

Product variant edit:
Before:

After:

Without the variant name:

Channels edit:
Before:

After:

And while trying to unsuccessfully remove the name:

After (translation of names to Admin locale)

[pjedrzejewski]

IIRC the reason to use codes was to avoid issues when editing. Because if you try to change name to empty, the breeadcrumb will take the data from the entity, which will have empty value bound by the forms logic... :)

[vvasiloi]

IIRC the reason to use codes was to avoid issues when editing. Because if you try to change name to empty, the breeadcrumb will take the data from the entity, which will have empty value bound by the forms logic... :)

@pjedrzejewski resource.name|default(resource.code)? 😄

[CoderMaggie]

The editing issue is very minor compared to the logic of displaying codes (that are an internal property used for processing things), while we have names (that are designed to be displayed everywhere). :)

I guess the weirdy forms' logic is not an issue that should be solved by displaying our immutable codes instead of names.

Although I will use the tip from @vvasiloi for now, thanks 💪

[Zales0123]

Could you provide some "before" and "after" screenshots? 🐎

[Zales0123]

@CoderMaggie rebase should fix the build :)

[GSadee]

Thank you, Magdalena! 🎉