[isthmus] CLI failures in native image due to undefined proxy classes

[vbarua]

Queries like

./isthmus -c 'CREATE TABLE foo(a VARCHAR);' "SELECT a FROM foo"

work in Isthmus, however when a GROUP BY is added

./isthmus -c 'CREATE TABLE foo(a VARCHAR);' "SELECT a FROM foo GROUP BY a"

The CLI fails with

Proxy class defined by interfaces [interface org.apache.calcite.rel.metadata.BuiltInMetadata$ColumnUniqueness] not found.

This also appears to happen with SELECT DISTINCT queries.

There does appear to be some configuration around proxy classes, but it is possibly insufficient.

substrait-java/isthmus/proxies.json

Line 6 in ce0f1ee

["org.apache.calcite.rel.metadata.BuiltInMetadata$ColumnUniqueness$Handler"],