frost-textarea should support text alignment

[sandersky]

frost-textarea is missing the align property found on frost-text. I think this property should be added in case a consumer of this project wants to support RTL languages/locales.

[notmessenger]

Development notes for when this is implemented:

Per https://html.spec.whatwg.org/multipage/form-elements.html#the-textarea-element there is no align property supported on textarea elements. There is however a dir that should be used:

Set the element's dir attribute to "ltr" if the user selected a left-to-right writing direction, and "rtl" if the user selected a right-to-left writing direction.

The API that should be exposed on frost-textarea should be the dir attribute and frost-text should be changed as well (though this change should be introduced via a deprecation and continued support of the align property)

[sandersky]

I believe align still holds value on the frost-text component as it is used for numeric values (generally numbers are aligned to the right).