always return sub value

[Janim007]

python sub method always return the original value even if there was no match and replacement.
to be consistent with python, this PR propose to remove checking if value hasn't changed and return the original value as it as.
example:

>>> re.sub(r'foo', 'bar', 'github')
'github'

[michaelmior]

@Janim007 Is there a specific problem this causes in the existing code? Could you add a test for such a case?

[torbenw]

@michaelmior I have some examples for why I think the current behavior is a problem:

Exp: orders[*].type
Res: [('orders.[0].type', 'type-1'), ('orders.[1].type', 'type-2')]

Exp: orders[*].type.`sub(/type-1/, Type1)`
Res: [('`this`', 'Type1')]

Exp: orders[*].type.`sub(/type-2/, Type2)`
Res: [('`this`', 'Type2')]

Exp: orders[*].type.`sub(/type-1/, Type1)`.`sub(/type-2/, Type2)`
Res: []

Exp: orders[*].type.`sub(/type-1/, Type1)`.`sub(/Type1/, Type1-1)`
Res: [('`this`', 'Type1-1')]

Exp: orders[*].type.`sub(/type-9999/, Type9999)`
Res: []

If I want to do a replacement for 1 of the values I will not get any of the other values.
If I want to do a replacement with different replacement strings for more than 1 value that is also not be possible.
If I use a regex with no match in my results (type-9999) I will not get any values.