Python: Fix query names that inclde __ (dunder)

Without backticks, the text UNDERSCORE UNDERSCORE eq UNDERSCORE UNDERSCORE would
be considered to make things bold in our markdown output, making the query info
look strange.

Example https://codeql.github.com/codeql-query-help/python/py-slots-in-old-style-class/

python/ql/src/Functions/ExplicitReturnInInit.ql

@@ -1,6 +1,6 @@
 /**
- * @name __init__ method returns a value
- * @description Explicitly returning a value from an __init__ method will raise a TypeError.
+ * @name `__init__` method returns a value
+ * @description Explicitly returning a value from an `__init__` method will raise a TypeError.
  * @kind problem
  * @tags reliability
  *       correctness

python/ql/src/Functions/InitIsGenerator.ql

@@ -1,6 +1,6 @@
 /**
- * @name __init__ method is a generator
- * @description __init__ method is a generator.
+ * @name `__init__` method is a generator
+ * @description `__init__` method is a generator.
  * @kind problem
  * @tags reliability
  *       correctness

python/ql/src/Functions/IterReturnsNonIterator.ql

@@ -1,6 +1,6 @@
 /**
- * @name __iter__ method returns a non-iterator
- * @description The '__iter__' method returns a non-iterator which, if used in a 'for' loop, would raise a 'TypeError'.
+ * @name `__iter__` method returns a non-iterator
+ * @description The `__iter__` method returns a non-iterator which, if used in a 'for' loop, would raise a 'TypeError'.
  * @kind problem
  * @tags reliability
  *       correctness

python/ql/src/Functions/IterReturnsNonSelf.ql

@@ -1,6 +1,6 @@
 /**
- * @name Iterator does not return self from __iter__ method
- * @description Iterator does not return self from __iter__ method, violating the iterator protocol.
+ * @name Iterator does not return self from `__iter__` method
+ * @description Iterator does not return self from `__iter__` method, violating the iterator protocol.
  * @kind problem
  * @tags reliability
  *       correctness

python/ql/src/Functions/OverlyComplexDelMethod.ql

@@ -1,6 +1,6 @@
 /**
- * @name Overly complex __del__ method
- * @description __del__ methods may be called at arbitrary times, perhaps never called at all, and should be simple.
+ * @name Overly complex `__del__` method
+ * @description `__del__` methods may be called at arbitrary times, perhaps never called at all, and should be simple.
  * @kind problem
  * @tags efficiency
  *       maintainability