vaadin-archetype-application must not create empty widget set about archetypes

[vaadin-bot]

Originally by @hesara

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This is related to #5416: automatic widgetset compilation should only take place when client side files (or project dependencies) have changed.

Apart from that enhancement, this ticket primarily concerns demos and "hello world" type of tests, not real applications. If the widgetset is not generated by default, the related Vaadin plug-in sections should still be in pom.xml (but commented out) and ideally there should be another goal for the Vaadin plug-in to create a new widgetset (#9918). Updating web.xml automatically in that case is problematic.

[vaadin-bot]

Originally by @tsuoanttila

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https://dev.vaadin.com/review/#/c/13155/

[vaadin-bot]

Originally by @tsuoanttila

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This has been replaced with a new approach. These changes should also be done for other archetypes as well. See https://dev.vaadin.com/review/#/c/13216/

[vaadin-bot]

Originally by @hesara

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Related also to #13404

[vaadin-bot]

Originally by @hesara

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Implemented for the basic archetype in a feature branch