Cleanup legacy arcctl deploy vomses/lsc from EGI
EGI does not have publicly opened API any longer. The legacy XML parsing code has no value at all. This MR clean it up.
Instead, arcctl will print URL to WebUI, where user can obtain information needed to construct the vomses/LSC files manually.
However, EGI do have proper REST API now, but it requires an API Token to access it. If someone will manage to host EGI VOMS API proxy (https://source.coderefinery.org/andrii/egi-voms-info) for NorduGrid, it will be possible to write the code to query the proxy interface from arcctl.