Fix #20451: block_view_gui for a manual fetched block don't use override templates

eZPageBlock->fetch calls **new eZPageBlock** which returns an eZPageBlock with several attributes, none of which are the **type** and **view** expected (I supposed, based on the debug output) by the rendering template.

With this patch:

**type** value is found in **block_type** therefore the assignation is linear.

I could not find **view** anywhere, but I could not find it either a way to select it while creating the block in the admin interface. It seems to always refer to the first available in block.ini ViewList array. Therefore, I am just setting the attribute **view** to the first value from **ViewList**.

It all seems to render properly now, if I manually fetch a block with
  {def $myblock=fetch('ezflow', 'block', hash( 'block_id', <myBlockId>))}
  {block_view_gui block=$myblock}
  {undef $myblock}