Statements ignored by the parser do not implement QueryPartInternal

[lukaseder]

When the parser encounters a statement that it ignores (e.g. the new CREATE EXTENSION statement support from #8324), it produces a proxy that currently doesn't implement QueryPartInternal. All QueryPart instances are expected to also implement QueryPartInternal by all of jOOQ's internals. Currently, we can get this kind of ClassCastException:

java.lang.ClassCastException: class com.sun.proxy.$Proxy11 cannot be cast to class org.jooq.QueryPartInternal (com.sun.proxy.$Proxy11 and org.jooq.QueryPartInternal are in unnamed module of loader 'app')
	at org.jooq.impl.AbstractContext.visit0(AbstractContext.java:410)
	at org.jooq.impl.AbstractContext.visit(AbstractContext.java:218)
	at org.jooq.impl.DefaultDSLContext.renderInlined(DefaultDSLContext.java:720)
	at org.jooq.impl.AbstractQueryPart.equals(AbstractQueryPart.java:161)
	at org.junit.Assert.isEquals(Assert.java:131)
	at org.junit.Assert.equalsRegardingNull(Assert.java:127)
	at org.junit.Assert.assertEquals(Assert.java:111)
	at org.jooq.test.util.BaseTest.assertEquals(BaseTest.java:89)
	at org.jooq.impl.AbstractParserTest.assertQueryEquals(AbstractParserTest.java:210)
	at org.jooq.impl.ParserDDLStatementTest.testCreateExtension(ParserDDLStatementTest.java:91)

This is probably mostly a unit / integration test issue, but it should still be handled correctly.

[lukaseder]

This fix depends on a new jOOR feature: jOOQ/jOOR#83. We'll upgrade the dependency to 0.9.12: #8909