mgr/dashboard: Splitting tenant$user when creating rgw user

mgr/dashboard: Splitting tenant$user when creating rgw user

Fixes: https://tracker.ceph.com/issues/47378
Signed-off-by: Nizamudeen A <nia@redhat.com>
(cherry picked from commit 7f4387d34fd073a3b0d8c828fecdc5df4b498122)

 Conflicts:
	src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/rgw-user-details/rgw-user-details.component.html
    -  Accepted the current changes and pasted the new change
	src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/rgw-user-form/rgw-user-form.component.ts
    -  Accepted incoming change and changed const modalRef =
       this.ModalService.show(RgwUserSubuserModalComponent); to const modalRef = this.bsModalService.show(RgwUserSubuserModalComponent);
    -  Made some modification in getUID() function to adapt with octopus
	src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/rgw-user-list/rgw-user-list.component.ts
    -  Accepted the current change and pasted the new change. Changed
       the $localize to this.i18n to match the octopus way