SchemaMigrator/SchemaValidator - add tests for corner cases

[gbadner]

There are some corner cases that are covered by ORM tests. They should be migrated to Reactive to make sure they work properly.

Here are some ORM SchemaMigrator tests that should be reviewed for possible inclusion in Hibernate Reactive:

SchemaUpdateTableBackedSequenceTest
CrossSchemaForeignKeyGenerationTest
UniqueConstraintDropTest
MySQLDropConstraintThrowsExceptionTest
SchemaMigrationTargetScriptCreationTest
SchemaMigrationToOutputScriptTest     -> @RequiresDialect(H2Dialect.class)
SchemaMigratorHaltOnErrorTest        -> skip DB2 & Derby
SchemaUpdateProceedOnErrorTest
SchemaUpdateSchemaNameTest     ->  @RequiresDialect(MySQL5Dialect.class)

Here are some ORM SchemaValidator tests that should be reviewed for possible inclusion in Hibernate Reactive:

LongVarcharValidationTest
NumericValidationTest
GroupedSchemaValidatorImplTest       -> @RequiresDialect(H2Dialect.class)
IndividuallySchemaValidatorImplConnectionTest       -> @RequiresDialect(H2Dialect.class)
IndividuallySchemaValidatorImplTest       -> @RequiresDialect(H2Dialect.class)
SchemaToolTransactionHandlingTest

[gbadner]

I don't think they all need to be added. I'll take a look at these and see which ones we need.

[DavideD]

I think we cover these cases, we will fix errors when they present themselves