Issue 49999 - Finish up the transfer to React
    
    Description: Move plugins.es6 to index.es6 so we can
    properly navigate using old nav-bar. New React entry points
    should be added to the index.es6.
    Add a make target for manual Cockpit UI building:
    'make 389-console' and a target to node_modules.mk 'eslint-fix'.
    Fix a few CSS issues.
    
    https://pagure.io/389-ds-base/issue/49999
    
    Reviewed by: mreynolds, mhonek (Thanks!)