Support and extend conditions in native broadcast nested loop joins #2541

Is your feature request related to a problem? Please describe.
Native broadcast nested loop joins currently reject join conditions, preventing native execution of non-equi joins such as l.value < r.value.

The native broadcast join implementation can evaluate these conditions using empty equality keys, but its sort-merge fallback also needs to handle that case.

Describe the solution you'd like

• Pass broadcast nested loop join conditions to the native broadcast join implementation and validate them through the existing join-condition configuration.
• Retain the existing build-side restrictions for supported broadcast join orientations.
• Use a constant sort key when a join without equality keys falls back to sort-merge execution.
• Avoid advertising output ordering for joins without equality keys or when sort-merge fallback is enabled.
• Add native and Spark regression tests covering conditions, projections, multiple probe partitions, configuration, and forced fallback.