Feature addition: Users can now provide custom BBOX information for WCS layers

[HaroldHormaechea]

This feature update was pending from a discussion in which it was stated it would be useful to be able to define the image extent to be downloaded to save on bandwidth and improve performance.

It allows users to define the actual extent of the image they wish to download, both during static viewing and when generating animations. This way it will not be neccesary to download a whole map when the area of interest is smaller, and the users will be able to create and play animations much faster by discarding areas they do not need.

It only works for WCS, because QGIS WMS provider ignores BBOX parameters in the URI. Despite this, I kept the required code implemented so if a feature request is sent to QGIS for BBOX information given in the URL to be saved, it'll be easy to implement and test.

There have been a few UI changes to make this possible:

• Static visor UI: The bounding box information is now displayed in QLineEdit objects, instead of QLabel, to make them editable.
• Animation add WCS layer UI: added similar QLineEdit objects.

[beneditobordonau]

Thanks Harold,

I'll review the modifications as soon as possible

[beneditobordonau]

Done. We incorporated it to master Thanks