xml-builder tool -- the channel page is not self-identifying

[rcasey-earthscope]

When using the xml-builder for new stations, once the user gets to a channel, there is nothing to indicate that we are talking about a channel or sensor. The user is instead asked to enter a location code only, there is no offered channel label, and the user has to enter epoch times by hand.

Instead, this panel should have something in the title or maybe the first entry field to indicate a channel name. Also, the epoch times should be equal to that of the parent station when first presented, subject to change. Even better would be, in the case of multiple channels being created, every time the start or end time is changed, that is globally carried forward to the next channel, as they are likely the same for a given epoch.