Translation fixes

[chindris]

Fixes included in this PR:

• the menu link description and label are now language aware (have the interface language in response cache context)
• the proper language is set for using the translation system, when executing a callable in a language context.
• the config override language is set, when executing a callable in a language context, so that config entities (like menus) are loaded using the proper translation.

This should fix: #773

[codecov]

Codecov Report

Merging #809 into 8.x-3.x will increase coverage by 0.11%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##             8.x-3.x     #809      +/-   ##
=============================================
+ Coverage      79.46%   79.57%   +0.11%     
+ Complexity      1280     1277       -3     
=============================================
  Files            192      192              
  Lines           3170     3178       +8     
=============================================
+ Hits            2519     2529      +10     
+ Misses           651      649       -2

Impacted Files	Coverage Δ	Complexity Δ
...c/Plugin/GraphQL/Fields/MenuLink/MenuLinkLabel.php	100% <ø> (ø)	2 <0> (ø)	⬇️
...core/src/Plugin/GraphQL/Fields/Menu/MenuByName.php	100% <ø> (+16.66%)	4 <0> (-5)	⬇️
...in/GraphQL/Fields/MenuLink/MenuLinkDescription.php	0% <ø> (ø)	2 <0> (ø)	⬇️
src/GraphQLLanguageContext.php	90% <100%> (+5.78%)	8 <1> (+2)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update eb3bcc8...54607d5. Read the comment docs.

[JohnAlbin]

Works great! 🎆