Consolidate E2E `dashboard` specs (#33073)

* Consolidate "create new dashboard" workflow

* Consolidate "add new dashboard card" tests

* Remove redundant repro for 25705

* Group and consolidate "title and description" tests

* Move repro 26826 to the main `dashboard` corpus

* Fix `visualization-options` spec name

* Make `dashboardHeader` more specific

* Consolidate "duplicate dashboard" tests

* Clean up and consolidate all dashboard management test

* Fix test failure

https://www.deploysentinel.com/ci/runs/64d9eb30fa6644982d115267

* Fix dashboard auto apply filters test failure

https://www.deploysentinel.com/ci/runs/64d9e91c7b3e6a1ddb9363c8

* Fix custom homepage test

https://www.deploysentinel.com/ci/runs/64d9e9a8f048784ce96aedf2

* Another attempt to fix a failing test

* Bring back a test removed during rebase