Allow more control over terminal input via component API

[jonmbake]

Is your feature request related to a problem? Please describe.
The API to the component does not allow much control over input behavior. For example, setting a value or performing some action on input change.

Describe the solution you'd like
Add an InputController prop that allows setting input value and listening for input change. The API could be something like:

class InputController
  + triggerInputChange(String input)
  + onInputChange(String input)
  + onInputReceived(String input)

Describe alternatives you've considered
Some alternatives were discussed in #5

Additional context
See #5

[joranbeasley]

please fix arrow keys while you are at it :)