RedisRaft adopts new configuration API: redis/redis#10285

After this commit, RAFT.CONFIG will not exist anymore. CONFIG command will be used instead.

Usage:

• Command: config set raft.addr 127.0.0.1:8000 and config get raft.id
• CLI: ./redis-server --port 5001 --loadmodule redisraft.so --raft.id 3 --raft.addr 127.0.0.1:8000
• Config file:

  ...
  port 5000
  dbfilename redis.rdb
  loadmodule /home/ozan/Desktop/redisraft/redisraft.so
  raft.addr 10.0.3.69:5022
  raft.slot-config 0:5460
  

Breaking changes

1. CONFIG command will be used instead of RAFT.CONFIG

2. Configuration parameters will require raft. or --raft. prefix.

3. Renamed some configuration parameters:

   Old name	New name
   raft-log-filename	log-filename
   raft-interval	periodic-interval
   raft-response-timeout	response-timeout
   raft-log-max-cache-size	log-max-cache-size
   raft-log-max-file-size	log-max-file-size
   raft-log-fsync	log-fsync

   Reasoning: As all parameters now have raft. prefix, parameters already starting with raft would include too many "raft"s :). With this change, instead of raft.raft-log-fsync, we'll have raft.log-fsync.

4. join-timeout config was in seconds. Now, it is in milliseconds.
   connection-timeout config was in microseconds. Now, it is in milliseconds.

   Reasoning: Now, all timeout configs are in milliseconds. I suggest keeping it that way for future configuration parameters as well. This is easy to remember and it prevents confusion.

Jepsen part: RedisLabs/jepsen-redisraft#3

Closes: #306