Accumulated changes for message queue (#6600)

* rename

* set agent address

* refactor

* add agent sub

* pub messages

* grpc new client

* can publish records via agent

* send init message with session id

* fmt

* check cancelled request while waiting

* use sessionId

* handle possible nil stream

* subscriber process messages

* separate debug port

* use atomic int64

* less logs

* minor

* skip io.EOF

* rename

* remove unused

* use saved offsets

* do not reuse session, since always session id is new after restart

remove last active ts from SessionEntry

* simplify printing

* purge unused

* just proxy the subscription, skipping the session step

* adjust offset types

* subscribe offset type and possible value

* start after the known tsns

* avoid wrongly set startPosition

* move

* remove

* refactor

* typo

* fix

* fix changed path

.gitignore

@@ -87,7 +87,6 @@ other/java/hdfs/dependency-reduced-pom.xml
 
 # binary file
 weed/weed
-weed/mq/client/cmd/weed_pub_kv/weed_pub
 docker/weed
 
 # test generated files
@@ -95,7 +94,4 @@ weed/*/*.jpg
 docker/weed_sub
 docker/weed_pub
 weed/mq/schema/example.parquet
-docker/weed_pub_kv
-docker/weed_pub_record
-docker/weed_sub_kv
-docker/weed_sub_record
+docker/agent_sub_record