Add "text-select" to focus-on, click-on, etc. commands

[bob2517]

The use case is for moving a cursor back across several digit fields in a form, or "tel" inputs in my case, and highlighting what is there already, such as when an user has to enter 6 digits for an authentication form and you want it to move to the next field automatically and have the arrow keys move back and forth in the fields.

Solution is adding text-select to focus-on-next, .etc commands.

Eg. (showing the syntax of the command only)

.
.myField:keydownArrowLeft {
    focus-on-next: .myField text-select;
}

Now on branch.