Fixed persisted viewmodel in Chrome

[GerardSmit]

See #685 for more information. Maybe we should add an setting in DotvvmConfiguration to configure this behaviour incase someone uses an element selector that searches for input[type=hidden] in his code.

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fixes #685

[exyi]

Seems ok to me (although I'd be happier if the hidden field worked in Chrome...).

I don't think we need the configuration option, there is no reason to find that element by type when it has id="__dot_viewmodel_root"

[GerardSmit]

Actually, I just realized that input[type=input] can have issues with autocomplete. Maybe we should add the attribute autocomplete=off on the input just to be sure.

[GerardSmit]

This solution will be re-written with the History API, see #685 (comment) for more information.