refactor(i18n): More accurate emotion translations to improve clarity

- Matches training data better.

- Easier to understand the purpose of the sliders.

- Consistent use of adjectives so that the user interface looks nicer.

- Reasoning:

* Hate -> Disgusted: The original Chinese word expresses disgust, not hatred. Hatred is an angry emotion and was confusing since there's already an Angry slider.

* Low -> Melancholic: The original Chinese word talks about feeling melancholic / down low, a state of slow speech and subdued emotions, which is not the same as sadness or depression. The word "Low" is very confusing for this emotion. The most accurate word for the emotion is "melancholic".

* Neutral -> Calm: The original Chinese word describes a state of being at peace and tranquility. It's not a neutral, non-emotional state. It's a state of being calm and relaxed.

tools/i18n/locale/en_US.json

@@ -11,11 +11,11 @@
   "喜": "Happy",
   "怒": "Angry",
   "哀": "Sad",
-  "惧": "Fear",
-  "厌恶": "Hate",
-  "低落": "Low",
-  "惊喜": "Surprise",
-  "平静": "Neutral",
+  "惧": "Afraid",
+  "厌恶": "Disgusted",
+  "低落": "Melancholic",
+  "惊喜": "Surprised",
+  "平静": "Calm",
   "情感描述文本": "Emotion description",
   "请输入情感描述文本": "Please input emotion description",
   "高级生成参数设置": "Advanced generation parameter settings",