Upgrade to OpenROADM 7.1.0 network models

Upgrade to OpenROADM 7.1.0 network models

- Replace existing OpenROADM network models with version 7.1.0
- New version of transportpce-topology model to suppport 7.1.0 models
- common module: add constants to manage fixed and flex grid,
  add GridUtils class to init frequencies map
- update networkmodel module: update import version, update unit tests
- update renderer module: update import version, replace wavelength
  with frequencies map, update unit tests
- update olm module: update import version
- update pce module: update import version, replace wavelength with
  frequencies map (from 7.1 models), update unit tests and data test
  files
- update tapi module: update import version and data test file
- update lighty module: update import version
- update functional tests: update response check, add constants and
  functions to compute freq map, update data test files

Note that in pce, tapi modules and functional tests, there is
a major update in test data files: replacement of
available-wavelength
with avail-freq-maps which contains a base64 encoded 96 bytes
representing available frequency

JIRA: TRNSPRTPCE-259
Signed-off-by: manuedelf <emmanuelle.delfour@orange.com>
Change-Id: Iaf95e04232283f6adf08ef41b394c1cd0fca2354