feat: navigation callbacks

[Tiagoperes]

• Renames params in navigation actions to state, which is what they actually are. This has been done to avoid confusion with route params and query params.
• Implemented events in navigation. Navigation events allows the next page to report something to the calling page. While state send information from the calling page to the target page, events do the opposite.
• Implemented action triggerViewEvent which triggers an event passed in the navigation. It accepts the event name and the value for the implicit state to be created.
• State declaration now accepts expressions! i.e. a state can be initialized with the value of another state or operation.
• New operation: object. This is necessary because Nimbus Script has no support for object literals yet. With this operation, one can create an object by calling @{object('key1', 1, 'key2': 'hello', 'key3', true)} for instance.
• New operation: array. This is necessary because Nimbus Script has no support for array literals yet. With this operation, one can create an array by calling @{array('element1', 2, 'element3', 4, null, 6)} for instance.