Test PR for new Retry Framework

[kakwok]

PR description:

Implements a RetryActionBase class for different types of action to be taken upon the need to retry.
SonicClientBase will have a list of RetryAction pointers initialized at construction.
The client will retry the list of actions one-by-one until every actions is no-longer suitable to retry.

An example configuration may look like this:

   Client = cms.PSet(
        mode = cms.string("Sync"),
        factor = cms.int32(-1),
        wait = cms.int32(10),
        allowedTries = cms.untracked.uint32(0),
        fails = cms.uint32(0),
        Retry = cms.VPSet(
              Action1 = cms.PSet(
                  retryType = cms.string("RetrySameServerAction"),
                  allowedTries = cms.untracked.uint32(4)
              ),
                Action2 = cms.PSet(
                  retryType = cms.string("RetrySomeOthersAction"),
                    ...
              ),
        )
    ),

[kpedro88]

const std::string&

[kpedro88]

const std::string&

[kpedro88]

should rebase on latest 15_1_X prerelease (to incorporate cms-sw#47748)