This patch fixes the problem that toggling one of the options in the
user account dialog will automatically submit the form.
The problem got introduced as a combination of the recent accessibility
fixes where some elements got turned into HTML button elements to make
them keyboard accessible. Doing that, I did not realize that the default
type of a button is `submit` [1]. This causes no problems at most places,
but will cause problem within a form (e.g. the user account settings)
where toggling an option is now identical to clicking submit.
This patch fixes the issue by setting the `type` attribute to `button`.
Not only for the toggle switch, but also for a few other elements which
have been recently converted to buttons.
[1] https://www.w3.org/TR/2011/WD-html5-20110525/the-button-element.html#attr-button-type
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