feat(server): support restore command - refactor load class (#343)

[boazsade]

feat(server): adding support for the restore command (#343)

feat(server): adding support for the restore command, update the api status (#343)

Signed-off-by: Boaz Sade [email protected]

• This add support for the restore command. This command is the complementary of the dump command.
• There is a code refactor to the class RdbLoader, but it is mostly moving some of the code so that it can be used for cases such as loading a single object from RDB format without the key - which is the case for the restore command.