Add and Fix docs for split_unescape

[ajratnam]

split_unescape function didn't have its docstring completly written.
The example in the doc had a mistake, raw strings also cannot end with a single backslash.

[fliiiix]

Do you have any idea why

>>> split_unescape(r'foo\|bar', '|')
['foo|bar']

leads to
radish/utils.py:190: DeprecationWarning: invalid escape sequence |

because i think that should not happen because we us a raw string

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (a515e15) 87.26% compared to head (46580cc) 87.26%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #460   +/-   ##
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  Coverage   87.26%   87.26%           
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  Files          39       39           
  Lines        2380     2380           
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  Hits         2077     2077           
  Misses        303      303           

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unittests	87.26% <ø> (ø)

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Files	Coverage Δ
radish/utils.py	69.38% <ø> (ø)

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[ajratnam]

I think that's because you normally use r strings to unescape any escaped sequence
but in our case \| isn't an escape sequence so nothing is being escaped

>>> r'\|' == '\|'
True
>>> print(r'\|')
\|
>>> print('\|')
\|

imo, the fix for it would be using normal string with \\ or I think it maybe some issue with flake8 also

[ajratnam]

Yeah, I changed it to that, and my linter doesn't show me that error anymore. I think this fixes #443

[fliiiix]

thanks again merged and release with 0.17.0