BasePhaseLoader: Allow parameters to be specified in 'options' blocks

This allows ECD blocks like:

'''
  - inherit: jdbc.sqlite.cse.phase
    name: information-extractor
    options: |
      - inherit: phases.ie.fixedregex
        regex: "\\$[^.]*"
'''

i.e. specifying parameters inline in the options block rather than only
in the inherited ECDs.