cockpit-components-listing: new 'initiallyActiveTab' attribute
cockpit-components-listing: new 'initiallyActiveTab' attribute

Opens a tab on index of 'initiallyActiveTab' when initially rendered.
Otherwise defaults to first tab (0 index)

Closes #8014
Reviewed-by: Peter <a316049dd34607c62d4611d63ab22a6454add223@redhat.com>

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