[Feature Request]: Enhancement Request for Table Input: Explicit Parameter Mapping and Option to Preserve Incoming Fields

### What would you like to happen?

In its current form, the Table Input transform has two limitations when used with the options “Insert data from transform” and “Execute for each row”:

No explicit parameter-mapping interface.
When the transform receives upstream fields and uses ? placeholders in the SQL, Hop automatically assigns parameters based on field order. This behavior is implicit and error-prone, especially when several fields arrive in the input stream. Users have no way to select which fields should map to each parameter.

Upstream fields are lost after execution.
When the SQL is executed, the transform outputs only the fields returned by the query. The fields coming from previous transforms do not flow forward unless additional steps are added.
This breaks the data stream and forces unnecessary workarounds.

Requested Improvements:

Parameter Mapping UI
Add a configuration panel that allows users to explicitly map each ? placeholder in the SQL to a specific upstream field.
This would eliminate ambiguity, reduce errors, and prevent users from resorting to Database Join solely to achieve parameterized execution.

Option to Preserve Input Stream Fields
Add a checkbox such as “Keep incoming fields”.
When enabled, the output rows should include both:

the original upstream fields, and

the fields returned by the SQL query.

Why this enhancement is important:

It enables parameterized SQL execution directly in Table Input, without falling back to slower transforms like Database Join.

It keeps the data stream intact, simplifying pipeline design.

It gives users explicit control over parameter mapping, improving reliability and usability.

This change would significantly enhance the flexibility and efficiency of workflows that rely on dynamic SQL parameters.

### Issue Priority

Priority: 3

### Issue Component

Component: Transforms