fix(LIBS-799): skip header i18n initialisation

[kabaros]

passes a flag to the Header component to skip i18n initialisation as this is handled by the platform

screenshots

ar_EG using translation when there is a match, and falling back to ar when no match

ar_IQ falling back to ar

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[KaiVandivier]

I tested this out with a number of conditions, refreshing a number of times on v42 to test for race conditions, and it's working: 🎉

Case	V42	v41
ar_EG	Translations with fallbacks successful	All good
Ar	All good	All good
pt_BR	All good	All good
Pt	All good	All good
uz_Cyrl	This doesn't work unfortunately*	Works; doesn’t fall back to uz_Cyrl or uz though (Moment works)
En	Works	Works

* uz_Cyrl doesn't work due to the janky formatting for this locale in v42 (uz-UZ-x-lvariant-Cyrl). Intl.Locale('uz-UZ-x-lvariant-Cyrl') in localeUtils.js in the adapter is where it stops

[Interestingly, going straight to i18n.changeLanguage('uz-UZ-x-lvariant-Cyrl') will end up falling back to uz (but not uz_Cyrl)... but we don't have any translation files for just uz, so that's not very helpful]

Conclusion I think the backend needs to fix that weird formatting, and this is good to go!