test/unit/merge: Clone resolveConflictAsync arguments
test/unit/merge: Clone resolveConflictAsync arguments

  Sinon spies do not clone the spied function calls arguments. Also, in
  Javscript, object are passed as references in function calls.

  This means that if an object argument is mutated after the spied
  function call, the spy call argument will be the mutated version and
  not the original version.

  This is an issue when trying to check expectations on
  `Merge.resolveConflictAsync()` calls because the `doc` argument passed
  to this function will can be mutated after and our expectations will
  fail.

cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop