Issue 50884 -  Health check tool DSEldif check fails
    
    Bug Description:  dsconf healthcheck was failing depending how the
                      server id entered.  Using "slapd-INSTANCE" vs
                      "INSTANCE" produced different results.
    
    Fix Description:  Normalize the instance name by always stripping
                      off "slapd-".  Also fixes similar issue when ~/.dsrc
                      is used.
    
                      Fixed the RI plugin lint report's inconsistent IDs
    
                      Fixed issue how flipend was being called for read-nsstate.
    
    relates:  https://pagure.io/389-ds-base/issue/50884
    
    Reviewed by: spichugi & firstyear (Thanks!)
    
    Improve instance name handling robustness