Conrtol display of service <step> buttons

[EliL]

Services with a <step> produce the generic Cancel and Go Buttons. Sometimes these buttons have no function and can cause an error.

1. click identify (or select)
2. click Go button
3. error (basically null input instead of WKT)

Having options in the <step> to show-buttons="false" could be one approach. A less good approach might be to try and give ids such that things can then be visually controlled in the css. Another might also be catching these errors elsewhere. An empty search sort of does that I think.

The Go button after the tool has been used (some WKT exists) can be used to re-run the service with the same WKT. So the Go button does have some function here, although I'm not sure the ability to re-run the same tool with the same WKT input is important.

This is at least applicable to identify and select.

[bfischer]

transferred from ​https://github.com/geomoose/geomoose/issues/26