Schema changes int->tinyint and foreginkeys/indexes rename (#2922)

* Schema changes int->tinyint and foreginkeys/indexes rename

* Optimize schema migration to do all related changes within one statement per table - i.e. no redundant table re-builds

* Foreign key checks disabled for huge dbs

* Merge unify and convergence schemas as they both do migrations on common tables - reduce downtime

* Rename unify schema

hawkbit-repository/hawkbit-repository-jpa-init/src/main/java/org/eclipse/hawkbit/repository/jpa/init/HawkbitFlywayDbInit.java

@@ -101,6 +101,7 @@ public class HawkbitFlywayDbInit {
                 .sqlMigrationSuffixes(SQL_MIGRATION_SUFFIXES)
                 .cleanDisabled(true)
                 .validateOnMigrate(true)
+                .ignoreMigrationPatterns("*:missing")
                 .envVars();
         if (CALLBACKS.length == 0) {
             if (callbackViaServiceLoader.length != 0) {