Do not automatically show sketches

[Pete-Y-CS]

No description provided.

[Sparrow0hawk]

This is feels like a tricky one re the behaviour the end user wants/is also quite a big change away from the current default. Couple of notes:

• This change means no scheme sketches will immediately be shown but the other previously opened layers will still be shown on the map
• Considering the previous point, is the desireable starting point for a user on the browse page just an empty map and they build layers up? Or do we want to remember some layers from the previous session?

I think we need to know what the desired starting point would be from users before fully committing to a change. Could we discuss with Nicos and any other inspectors using the Browse page about this?

Ignore the above, I think I get this change slightly better. Changing the default so that schemes aren't just automatically loaded whatever feels like a more sensible move that gives the user more control over the layers.