sharding (core): Add base sharding support.

Add `meta.args` for command line argument access.
Add command line argument support for shard number.
Add shard count to config file.
Add `meta.sharding` exposing shard properties.
Add shard number to logging methods.
Add shard number to data appid.

bot/main.py

@@ -1,4 +1,4 @@
-from meta import client, conf, log
+from meta import client, conf, log, sharding
 
 from data import tables
 
@@ -7,7 +7,12 @@ import core # noqa
 import modules  # noqa
 
 # Load and attach app specific data
-client.appdata = core.data.meta.fetch_or_create(conf.bot['data_appid'])
+if sharding.sharded:
+    appname = f"{conf.bot['data_appid']}_{sharding.shard_count}_{sharding.shard_number}"
+else:
+    appname = conf.bot['data_appid']
+client.appdata = core.data.meta.fetch_or_create(appname)
+
 client.data = tables
 
 # Initialise all modules