fix(scan): fix workspaces can't overlap nor be renamed

[smailio]

fix ANT-2768 and ANT-2773

[sylvlecl]

Let's wait until we decide what to do exactly:

• we should probably forbid nested workspaces in configuration
• we could "hide" (not return them in studies listing) studies belonging to worskpaces that are not configured anymore
• I think in desktop version, we should just forbid external workspaces, to me, they are not adapted to this use case. They raise too much questions in such unstable and user-defined environment.