Add no_traceback argument to :okexcept: option of ipython sphinx directive - #13751

- use local modified ipython_directive to add optional no_traceback
  argument to :ok_except: which prevents the (sometimes long) traceback
  from being printed (default is no argument, i.e. the traceback is
  printed) and enable the @okexcept pseudodecorator so that it can be
  applied to individual instructions instead of the whole block
- use local modified ipython_console_highlighting to enable syntax
  highlighting of exceptions without a traceback
- fix pylint warnings for ipython_directive.py and simplify
  "".join(["."] * x) to "." * x

The "# noqa: E999" after "@okexcept no_traceback" is necessary to
prevent flake8-rst from complaining about syntax errors as it
interprets the pseudodecorator as a real python decorator.

Items 1 and 2 can be reverted if github.com/ipython/ipython/pull/13751
gets merged upstream.

- use local modified ipython_directive to add optional no_traceback
  argument to :ok_except: which prevents the (sometimes long) traceback
  from being printed (default is no argument, i.e. the traceback is
  printed) and enable the @okexcept pseudodecorator so that it can be
  applied to individual instructions instead of the whole block
- use local modified ipython_console_highlighting to enable syntax
  highlighting of exceptions without a traceback
- fix pylint warnings for ipython_directive.py and simplify
  "".join(["."] * x) to "." * x

The "# noqa: E999" after "@okexcept no_traceback" is necessary to
prevent flake8-rst from complaining about syntax errors as it
interprets the pseudodecorator as a real python decorator.

In ipython_directive.py:1106, pylint complains about access to
self.content before its definition although it is defined in the base
class. That's why I added "# pylint: disable=access-member-before-definition"
to make the pre-commit hook pass.

Items 1 and 2 can be reverted if github.com/ipython/ipython/pull/13751
gets merged upstream.

- use local modified ipython_directive to add optional no_traceback
  argument to :ok_except: which prevents the (sometimes long) traceback
  from being printed (default is no argument, i.e. the traceback is
  printed) and enable the @okexcept pseudodecorator so that it can be
  applied to individual instructions instead of the whole block
- use local modified ipython_console_highlighting to enable syntax
  highlighting of exceptions without a traceback
- fix pylint warnings for ipython_directive.py and simplify
  "".join(["."] * x) to "." * x

The "# noqa: E999" after "@okexcept no_traceback" is necessary to
prevent flake8-rst from complaining about syntax errors as it
interprets the pseudodecorator as a real python decorator.

In ipython_directive.py:1106, pylint complains about access to
self.content before its definition although it is defined in the base
class. That's why I added "# pylint: disable=access-member-before-definition"
to make the pre-commit hook pass.

Items 1 and 2 can be reverted if github.com/ipython/ipython/pull/13751
gets merged upstream.