Refactor error messages and function signatures across multiple notebooks for clarity and consistency

- Updated error messages in Gauss method and numerical methods to use variables for better readability.
- Added return type hints to function signatures in various notebooks to improve code documentation.
- Corrected minor grammatical issues in docstrings for better clarity.
- Adjusted print statements and list concatenations for improved output formatting.
- Enhanced plotting functions to ensure consistent figure handling.

M1/Statistical Learning/TP5_Naive_Bayes.ipynb

@@ -227,7 +227,8 @@
    "source": [
     "sms = pd.read_csv(\"data/spam.csv\", encoding=\"latin\")\n",
     "\n",
-    "sms.head()"
+    "sms.head()\n",
+    "sms = "
    ]
   },
   {
@@ -243,7 +244,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "sms.rename(columns={\"v1\": \"Label\", \"v2\": \"Text\"}, inplace=True)"
+    "sms.rename(columns={\"v1\": \"Label\", \"v2\": \"Text\"})"
    ]
   },
   {