Ability to configure what no_multiline_whitespace_around_double_arrow fixes

[lstrojny]

no_multiline_whitespace_around_double_arrow is applied for arrow functions. That clashes with multi line formatting of arrow functions.

$fn = fn(string $someRatherLongVariableName) =>
    $someRatherLongVariableName === $theOtherPrettyLongVariableNameOneMightWantToCompareThingsWith;

no_multiline_whitespace_around_double_arrow will reformat this in the following way and apparently that is a conscious decision:

$fn = fn(string $someRatherLongVariableName) => $someRatherLongVariableName === $theOtherPrettyLongVariableNameOneMightWantToCompareThingsWith;

Wouldn't it make sense that the double arrow space formatting would either not apply to arrow functions at all or that it can be turned off and on for arrays or arrow functions?