feat: implement FileSelector component

[TahimiLeonBravo]

• define API
• Implement component
• add unit and integration tests

Define API

https://docs.google.com/document/d/1U2uJ6BVtBmRVD-n3vQ9m6LjvkF_9ZmYgSI70fZ8Mbow/edit?usp=sharing

Design

https://zpl.io/brZAy4e

Requirements

• It should accept the same attributes of the native input
• It should be work with redux-form
• It only should accept select or drag & drop files, not other elements.
• It only should allow select files, it not is possible to initialize your state with selected elements.

Unit test specs

fileSelector

• should render an input with type file
• should set the same generated value to the label htmlFor and the input id
• should set the tabIndex passed in the input element
• should set disabled in the input element if it is passed
• should set required in the input element if it is passed
• should pass a generated id to the error element and set the same id to the aria-describedby for the input when a error is passed
• should pass the right props to the Label component
• should render HelpText when bottomHelpText is passed
• should fire change event when a file is picked
• should fire focus event
• should fire blur event

getText

• should return placeholder when files is not defined
• should return placeholder when files is an empty array
• should return the name of the file when files has only one item
• should return a string with the length of files

containsFiles

• should return false when there is types different than "Files"
• should return false when types array is empty
• should return false when types array is undefined
• should return true when all types are "Files"