textarea: Create as separate block

Close #1033
I've made only basics yet: `common`+`desktop`, `BEMHTML`-templates, js, styles only for `islands` theme.
I didn't remove `input_type_textarea` to have ability to compare new block with it.
Если элемент disabled, то у него должна пропадать вся интеракивность, в том числе и возможность resize.