CRM_Utils_Array::pathMove - Add helper to move an item within array tree

[totten]

Overview

Adds a helper function to move items within an array tree, e.g.

$foodStuffs = [
  'fruits' => [
    'apple' => ['sweet' => TRUE],
  ],
  'veggies' => [
    'tomato' => ['sweet' => FALSE],
  ],
];

// Ruhroh. Tomato had a culinary classification, but we need botanical classification!
CRM_Utils_Array::pathMove($foodStuffs, ['veggies','tomato'], ['fruits', 'tomato']);
// Assert: $foodStuffs['veggies']['tomato'] ==> undefined
// Assert: $foodStuffs['fruits']['tomato'] ==> ['sweet' => FALSE]

[civibot]

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[totten]

jenkins, test this please

[seamuslee001]

This seems fine to me merging