base: user 'Login' and 'Register' button  addition

* Shows the 'Register' button if the value of
  'CFG_ACCESS_CONTROL_LEVEL_ACCOUNTS' is 0 or 1. (addresses #1943)

Signed-off-by: Eirini Psallida <eirini.psallida@cern.ch>
base: global tooltip activation

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>