Revert "rework Cliboard._getTextArea => @init"
Revert "rework Cliboard._getTextArea => @init"

for faster initing
reverted: commit c0cfe9da7aa3c0dc9b7051dcb9db335cf32791ac

gdh1995/vimium-plus,gdh1995/vimium-plus,gdh1995/vimium-plus