Extending support for Streaming Conformance mapping rule to more than join conditions

## Background
The current implementation of streaming conformance supports up to 5 join conditions. Unfortunately, we didn't find a way to support an arbitrary amount of join conditions since each number of arguments needs to be a separate UDF.

## Feature
Increase the maximum number of join conditions that can be used in the mapping rule for streaming (broadcast mapping rule) to at least 10 (the exact number is to be decided).

## Proposed Solution [Optional]
In order to support more join conditions, a pair of UDF generators need to be implemented for each number of arguments. One UDF generator for the mapping, the other is for the error column.

UDFs are defined in `BroadcastUtils` as `getMappingLambdaParamX()` and `getErrorLambdaParamX()` (where X is 1 to 5).
After 6 to 10 are added they are invoked from `getMappingUdf()` which needs to be extended too.

Start in BroadcastUtils by reading getMappingLambdaParamX() and getErrorLambdaParamX() for X=1..5, then inspect getMappingUdf() to trace how argument counts are selected. Confirm the agreed maximum before extending the supported range; done means the streaming broadcast mapping rule supports it through both the mapping and error UDF paths.

Scritto dal modello di indicizzazione a partire dal testo della issue.