Forbid `raise MyExc()` in except handler without `from`

Rule request

Thesis

This is the follow-up to #1184 issue. R100 rule is not covered in WPS.

Reasoning

This example does not see to catch problems with from absence:

try:
    some_dct['bar']
except KeyError:
    raise ValueError()

Also WPS329 doc cite such raise as example of correct code.

[webknjaz]

Sometimes you don’t want to process an exception on the current layer but want to log it there. In this case, you’d use a bare raise

def func2():
    try:
        do_something()
    except Exc1:
        log_it()
        raise


def func1():
    try:
        func2()
    except Exc1 as exc:
        actually_process_the_exception(exc)

Another case would be filtering out certain exception attributes. Like when an OSError happens, sometimes you want to only ignore one error code but you still want to pass-through other instances.

import errno

try:
    access_a_file()
except OSError as os_err:
    if os_err.errno != errno.ENOENT:  # we don't care if that thing does not exist but any other error mustn't be tollerated
        raise
    actually_process_the_exception(os_err)

[sobolevn]

Then it can be closed, thanks everyone!