SSP-2934 Fix misc Success Inidicator UI issues esp in admin

Also relax server-side rules on system-owned SI name/desc deletion
and always include a displayable value in server-side SI
evaluation responses. (The latter is an attempt to fix vertical
alignment of evaluated indicators in Main when at least one
indicator doesn't have a value. The latter also help discriminate
between 'no data' and 'error'.