shell: Remove obsolete menu tooltips
shell: Remove obsolete menu tooltips

Since the mobile nav redesign, the menu is wide enough to show all
labels without truncation, so there is no reason any more to just repeat
the exact same information in a tooltip.

Plus, this was using standard browser tooltips, which are inconsistent
with the usual jQuery/PatternFly ones that we use elsewhere. But these
don't work on the gray menu background.

martinpitt/cockpit,cockpit-project/cockpit,andreasn/cockpit,mvollmer/cockpit,martinpitt/cockpit,SotolitoLabs/cockpit,mvollmer/cockpit,SotolitoLabs/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,andreasn/cockpit,moraleslazaro/cockpit,andreasn/cockpit,stefwalter/cockpit,deryni/cockpit,moraleslazaro/cockpit,deryni/cockpit,mareklibra/cockpit,stefwalter/cockpit,mvollmer/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,garrett/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,deryni/cockpit,cockpituous/cockpit,deryni/cockpit,garrett/cockpit,mareklibra/cockpit,cockpituous/cockpit,mvollmer/cockpit,andreasn/cockpit,andreasn/cockpit,moraleslazaro/cockpit,stefwalter/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,andreasn/cockpit,cockpituous/cockpit,garrett/cockpit,deryni/cockpit,garrett/cockpit,garrett/cockpit,mareklibra/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,martinpitt/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,mareklibra/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,deryni/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,cockpituous/cockpit,cockpituous/cockpit,martinpitt/cockpit,mvollmer/cockpit,deryni/cockpit,martinpitt/cockpit,stefwalter/cockpit,stefwalter/cockpit,mareklibra/cockpit