mgr/dashboard:EC Profile creation form simplification and improvement

Fixes: https://tracker.ceph.com/issues/77369

Signed-off-by: Devika Babrekar <devika.babrekar@ibm.com>

 Conflicts:
	src/pybind/mgr/dashboard/frontend/src/app/ceph/pool/erasure-code-profile-form/erasure-code-profile-form-modal.component.html
-removed Directory field, as it is no longer needed in form