feat: add mysql election logic (#5694)

* feat: add mysql election

* feat: add mysql election

* chore: fix deps

* chore: fix deps

* fix: duplicate container

* fix: duplicate setup for sqlness

* fix: call once

* fix: do not use NOWAIT for mysql 5.7

* chore: apply comments

* fix: no parallel sqlness for mysql

* chore: comments and minor revert

* chore: apply comments

* chore: apply comments

* chore: add  to table name

* ci: use 2 metasrv to detect election bugs

* refactor: better election logic

* chore: apply comments

* chore: apply comments

* feat: version check before startup

.github/actions/setup-greptimedb-cluster/action.yml

@@ -8,7 +8,7 @@ inputs:
     default: 2
     description: "Number of Datanode replicas"
   meta-replicas:
-    default: 1
+    default: 2
     description: "Number of Metasrv replicas"
   image-registry: 
     default: "docker.io"

.github/workflows/develop.yml

@@ -576,9 +576,12 @@ jobs:
           - name: "Remote WAL"
             opts: "-w kafka -k 127.0.0.1:9092"
             kafka: true
-          - name: "Pg Kvbackend"
+          - name: "PostgreSQL KvBackend"
             opts: "--setup-pg"
             kafka: false
+          - name: "MySQL Kvbackend"
+            opts: "--setup-mysql"
+            kafka: false
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v4