When the user select a region, it should be better framed.

[guillesanz21]

When the user select a region, then:

• The zoom should be a little bit less than the actual zoom, so more geometries are shown.
• It shouldn't be centered at the middle of the screen, but at the middle of the part of the map that is showed (that is, width of the page minus width of the drawer).

[guillesanz21]

Less zoom fixed in commit 115c9e1