T/ckeditor5 engine/1555

[jodator]

Suggested merge commit message (convention)

Other: Remove Position, Range, Selection imports from engine/model and engine/view.

BREAKING CHANGE: The modelViewInsertion() converter now returns converter callback and requires model instance as a parameter.
BREAKING CHANGE: The modelViewRemove() converter now returns converter callback and requires model instance as a parameter.
BREAKING CHANGE: The modelViewChangeIndent() converter now returns converter callback and requires model instance as a parameter.
BREAKING CHANGE: The viewToModelPosition() converter now returns converter callback and requires model instance as a parameter.
BREAKING CHANGE: The modelToViewPosition() converter now returns converter callback and requires view instance as a parameter.

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Additional information

• Part of: T/1555: Expose Position, Range and Selection factories. ckeditor5-engine#1585.

[coveralls]

Coverage decreased (-44.1%) to 55.896% when pulling bc810c9 on t/ckeditor5-engine/1555 into 3d2ea98 on master.