[Feature Request]: Improve data profiling export and result aggregation

### What would you like to happen?

The Data Profiling feature provides useful metrics, but the current implementation makes the results hard to consume and analyze. Profiling outputs are shown per field and per metric, with no easy way to export all results into a single, consolidated Excel file.

Additionally, showing NOT NULL counts without referencing the total number of records is misleading. In this context, NULL counts are more valuable, as they directly highlight data quality issues. Ideally, profiling results should include total row count and null counts (or percentages) to give proper context.

This is a good concept, but the usability and output format need improvement to support real-world data quality analysis and reporting.

Acceptance criteria (example):
- Ability to export all profiling results into one Excel file
- One row per field with consolidated metrics
- Include total rows, null count (or null %)

### Issue Priority

Priority: 3

### Issue Component

Component: Hop Gui

Start by locating the Hop Gui Data Profiling implementation and its current profiling result display and export flow. Compare the existing output with the acceptance criteria: one Excel file, one row per field, consolidated metrics, total rows, and null counts or percentages; done means all criteria are supported.

Written by the indexing model from the issue text.