Hash key for plugin store table and limit plugin ID length (#7915)

* Hash plugin store keys and update column limits

* Limit plugin ID length on install

* Add note to manifest id and allow zero length keys

store/sqlstore/plugin_store.go

@@ -21,8 +21,8 @@ func NewSqlPluginStore(sqlStore SqlStore) store.PluginStore {
 
 	for _, db := range sqlStore.GetAllConns() {
 		table := db.AddTableWithName(model.PluginKeyValue{}, "PluginKeyValueStore").SetKeys(false, "PluginId", "Key")
-		table.ColMap("PluginId").SetMaxSize(100)
-		table.ColMap("Key").SetMaxSize(100)
+		table.ColMap("PluginId").SetMaxSize(200)
+		table.ColMap("Key").SetMaxSize(50)
 		table.ColMap("Value").SetMaxSize(8192)
 	}
 

store/sqlstore/upgrade.go

@@ -323,6 +323,10 @@ func UpgradeDatabaseToVersion44(sqlStore SqlStore) {
 }
 
 func UpgradeDatabaseToVersion45(sqlStore SqlStore) {
+	//TODO: Remove next two lines before 4.5 release. They're just here to fix CI servers
+	sqlStore.AlterColumnTypeIfExists("PluginKeyValueStore", "PluginId", "varchar(50)", "varchar(50)")
+	sqlStore.AlterColumnTypeIfExists("PluginKeyValueStore", "PKey", "varchar(200)", "varchar(200)")
+
 	//TODO: Uncomment when 4.5 is released
 	/*if shouldPerformUpgrade(sqlStore, VERSION_4_4_0, VERSION_4_5_0) {