feat(ai): add i18n strings for code blocks and plan mode

Add AI_CHAT_CODE_DEFAULT_LANG, AI_CHAT_CODE_COLLAPSE, AI_CHAT_CODE_EXPAND,
AI_CHAT_CODE_EXPAND_LINES, AI_CHAT_CODE_COLLAPSE_FOOTER, and
AI_CHAT_PLAN_REVISE_DEFAULT strings for internationalization.

Author: abose

src/nls/root/strings.js

@@ -1925,6 +1925,12 @@ define({
     "AI_CHAT_PLAN_APPROVE": "Approve",
     "AI_CHAT_PLAN_REVISE": "Revise",
     "AI_CHAT_PLAN_FEEDBACK_PLACEHOLDER": "What would you like changed?",
+    "AI_CHAT_PLAN_REVISE_DEFAULT": "Please revise the plan.",
+    "AI_CHAT_CODE_DEFAULT_LANG": "text",
+    "AI_CHAT_CODE_COLLAPSE": "Collapse",
+    "AI_CHAT_CODE_EXPAND": "Expand",
+    "AI_CHAT_CODE_EXPAND_LINES": "Click to expand - {0} lines",
+    "AI_CHAT_CODE_COLLAPSE_FOOTER": "Click to collapse",
     "AI_CHAT_QUESTION_OTHER": "Type a custom answer\u2026",
     "AI_CHAT_IMAGE_LIMIT": "Maximum {0} images allowed",
     "AI_CHAT_IMAGE_REMOVE": "Remove image",