Refactor OLM timers management

Refactor OLM timers management

OLM timer values are defined by OpenROADM whitepaper specifications.
For this reason, they are hardcoded with constants in the current code.
Though, there are at least 2 reasons to make them configurable:

1- At least one vendor product needs more than the OpenROADM whitepaper
   recommandation because it is not supporting GainLoss with
   target-output-power.

2- The OlmUtils constants are patched in functional tests to speed-up
   tests because the simulators needs less time to set the OLM up than
   real devices.

As a consequence,
- remove OlmUtils timers constants
- remove related command to patch them in tests scripts
- create a new constructor PowerMgmtImpl to allow any timers values
- modify OLM OSGi blueprint to set default values for these timers
  (Default values are the ones recommended in the OpenROADM whitepaper)
- modify lighty build to retrieve these timers from new CLI options
- adapt tests scripts and assembly ressources accordingly

JIRA: TRNSPRTPCE-496
Signed-off-by: guillaume.lambert <guillaume.lambert@orange.com>
Change-Id: I71f9bdfd38c11ea3427ca2e661cd3590bc2863bf