mgr/dashboard: Notification banners at the top of the UI have fixed height

mgr/dashboard: Notification banners at the top of the UI have fixed height

Fixes: https://tracker.ceph.com/issues/51575
Signed-off-by: Waad AlKhoury <walkhour@redhat.com>
(cherry picked from commit ea55a0b33db2990a67dca10a7a9bc476096cd4ee)

Conflicts:
src/pybind/mgr/dashboard/frontend/src/app/core/navigation/navigation/navigation.component.html
src/pybind/mgr/dashboard/frontend/src/app/core/navigation/navigation/navigation.component.scss
src/pybind/mgr/dashboard/frontend/src/app/shared/components/pwd-expiration-notification/pwd-expiration-notification.component.html
src/pybind/mgr/dashboard/frontend/src/app/shared/components/pwd-expiration-notification/pwd-expiration-notification.component.scss
src/pybind/mgr/dashboard/frontend/src/app/shared/components/pwd-expiration-notification/pwd-expiration-notification.component.spec.ts
src/pybind/mgr/dashboard/frontend/src/app/shared/components/telemetry-notification/telemetry-notification.component.html
src/pybind/mgr/dashboard/frontend/src/app/shared/components/telemetry-notification/telemetry-notification.component.spec.ts
src/pybind/mgr/dashboard/frontend/src/styles/defaults/_bootstrap-defaults.scss