Support serialization/deserialization for custom physical exprs in proto #11350

Is your feature request related to a problem or challenge?

We support serialization/deserialization for custom physical plan in proto, it's better to support custom physical expr as well.
For example, users might have a custom physical expr as predicate in ParquetExec.

Describe the solution you'd like

Like physical plan, we could have an extension node PhysicalExtensionExprNode in .proto, and add encode/decode physical expr methods in PhysicalExtensionCodec trait.

Describe alternatives you've considered

No response

Additional context

No response