CRM_Utils_Array - Implement pathUnset() method

[totten]

Overview

Add a helper function, pathUnset(), which removes an item from an array-tree. This complements existing helper functions pathGet(), pathIsset(), and pathSet() (which read and write values in an array-tree).

Technical Details

For example, suppose you have this array:

$arr = [
  'one' => '1',
  'two' => [
    'half' => 2,
  ],
  'three' => [
    'first-third' => '1/3',
    'second-third' => '2/3',
  ],
];

You may interact with the item three.first-third by calling:

CRM_Utils_Array::pathGet($arr, ['three', 'first-third']); // Returns string "1/3"
CRM_Utils_Array::pathIsset($arr, ['three', 'first-third']); // Returns bool "true"
CRM_Utils_Array::pathSet($arr, ['three', 'first-third'], "Revival!"); // Updates the item
CRM_Utils_Array::pathUnset($arr, ['three', 'first-third']); // Removes the item

[civibot]

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[eileenmcnaughton]

I think the case that this is consistent with existing functions + the unit test is fairly compelling

[eileenmcnaughton]

unrelated intermittent fail