feat: update translations for Vertex AI provider

- Changed 'Vertex AI' to 'GCP Vertex AI' in all language files
- Removed unused translation keys (vertexApiKeyLabel and vertexAuthMethodLabel)
- Updated translations for: ca, de, en, es, fr, hi, id, it, ja, ko, nl, pl, pt-BR, ru, tr, vi, zh-CN, zh-TW

Author: roomote

webview-ui/src/i18n/locales/ca/settings.json

@@ -55,10 +55,8 @@
 		"mistralProvider": "Mistral",
 		"mistralApiKeyLabel": "API Key:",
 		"mistralApiKeyPlaceholder": "Enter your Mistral API key",
-		"vertexProvider": "Vertex AI",
-		"vertexApiKeyLabel": "API Key:",
+		"vertexProvider": "GCP Vertex AI",
 		"vertexApiKeyPlaceholder": "Enter your Vertex AI API key",
-		"vertexAuthMethodLabel": "Authentication Method",
 		"vertexAuthMethodDescription": "Choose one authentication method: API Key, JSON Credentials, or Key File",
 		"vertexJsonCredentialsLabel": "JSON Credentials:",
 		"vertexJsonCredentialsPlaceholder": "Paste your service account JSON credentials",