Standardize Spanish on informal imperative

[1ec5]

The Castilian Spanish localization consistently uses the informal imperative form, while the (Latin American) Spanish localization uses a mix of formal and informal imperative forms. This change standardizes both localizations on the informal imperative form for consistency. If there’s a need for giving turn instructions more formally, that could be a separate es-formal localization.

Also updated remaining untranslated strings in both Spanish localizations.

Tasklist

• [x] Find and replace formal usage in Transifex
• [x] Pull translations from Transifex and update test fixtures
• [x] Add changelog entry
• [ ] Test with osrm-frontend (?)
• [x] Review

/cc @danpaz @Guardiola31337 @Sealos

[1ec5]

As a sanity check, I’ve verified that both Google Maps and Apple Maps use the informal imperative form across all the Spanish dialects you can choose from on iOS.