[FFM-11845]: Extend relevant constructors to enable storing previous and current FeatureConfig

[akiraqb]

• Added configuration flag to the base config.
• Added public client functions to get the snapshots
• If snapshot disabled, we will log in the message in the debug and return snapshot containing only current version.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}