Multi-select: implement dynamic loading

[tishoyanchev]

At the moment, users cannot dynamically pass a different array of options. They have to re-render the component. It is important to implement a dynamic loading logic that would allow the user to dynamically pass or edit the options array without having to re-render the component.

[pfafffabian-ifx]

@tishoyanchev The possibilites here are limited as stencil does not recognize when an array is modified, but only if the reference changes. However, I can

• Add a @Listen() that will update when the reference changes
• Add a method to the public api to manually trigger a reload (i.e. reload() or setOptions())