add unit test for batch issues

[hgschmie]

all of these tests should pass. But they don't. They fail with exotic errors such as

org.jdbi.v3.core.statement.UnableToCreateStatementException: No argument factory registered for 'User:2' of qualified type org.jdbi.v3.core.argument.ObjectArgument [statement:"INSERT INTO something (id, name) VALUES(:id, :name)", arguments:{positional:{}, named:{name:User:2,id:2}, finder:[]}]
        at org.jdbi.v3.core.statement.TestBatchProblems.testNonUniformBatchInsertsWithArguments(TestBatchProblems.java:136)

java.lang.ClassCastException: class java.lang.String cannot be cast to class java.lang.Integer (java.lang.String and java.lang.Integer are in module java.base of loader 'bootstrap')
        at org.jdbi.v3.core.statement.TestBatchProblems.testNonUniformBatchInserts(TestBatchProblems.java:113)```

[hgschmie]

Closing, still tracked in #2390.