Refactor: move mcp connection utilities to common (#11304)

### What problem does this PR solve?

As title

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

rag/nlp/__init__.py

@@ -155,13 +155,13 @@ def qbullets_category(sections):
             if re.match(pro, sec) and not not_bullet(sec):
                 hits[i] += 1
                 break
-    maxium = 0
+    maximum = 0
     res = -1
     for i, h in enumerate(hits):
-        if h <= maxium:
+        if h <= maximum:
             continue
         res = i
-        maxium = h
+        maximum = h
     return res, QUESTION_PATTERN[res]
 
 
@@ -222,13 +222,13 @@ def bullets_category(sections):
                 if re.match(p, sec) and not not_bullet(sec):
                     hits[i] += 1
                     break
-    maxium = 0
+    maximum = 0
     res = -1
     for i, h in enumerate(hits):
-        if h <= maxium:
+        if h <= maximum:
             continue
         res = i
-        maxium = h
+        maximum = h
     return res