Mitigate calculator deceiving behavior

[psychopatt]

Description of the new feature / enhancement

Do not offer a calculator solution when a number in the query doesn't match current locale.

For example, with french regional settings, one is expected to type in 4,017*5863,46 rather than 4.017*5863.46. But for both queries a calculator result is presented... with one dead wrong (screenshots from v0.64.1):

With such settings, it would be less prone to bad surprises to not present the first result at all, and maybe offer to fix the query with a result along the lines of

Did you mean 4,017*5863,46?

which, when selected, would replace the input and then present the (correct) result.

Scenario when this would be used?

This could avoid errors for anyone using the calculator on any computer where the regional settings are different from what one is used to.

Supporting information

This proposal is directly linked to the regional settings mentioned in #19741. The solutions from there (changing system or PT settings) are simple and correct, and the issue is easily worked around.

The problem is that it's taken me months before discovering this issue since even with the "wrong" decimal symbol results are wrong only in some circumstances (leading zeroes afer the decimal point) and correct in all other cases. That makes thoses cases viciously hard to detect (at least to me) and I probably have used false results without noticing it.