feat(legacy-plugin-chart-sankey): allow sort by metric

[ktmud]

🏆 Enhancements

Adding a "Sort by metric" checkbox control for Sankey chart. If selected, the query results will be sorted by metric in descending order. This is useful when there are many rows of data but it's not easy to regroup source and targets via custom SQL queries (e.g. when working with a datasource that does not support arbitrary SQL queries).

Also added a caveat warning for row limit:

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[codecov]

Codecov Report

Merging #831 (5c4fa7e) into master (8c992ae) will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #831      +/-   ##
==========================================
- Coverage   25.82%   25.82%   -0.01%     
==========================================
  Files         362      363       +1     
  Lines        7976     7977       +1     
  Branches     1066     1066              
==========================================
  Hits         2060     2060              
- Misses       5796     5797       +1     
  Partials      120      120              

Impacted Files	Coverage Δ
...ins/legacy-plugin-chart-sankey/src/controlPanel.ts	0.00% <0.00%> (ø)

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[villebro]

A by-thought: if there are many orphaned paths (=both source and target only used in a single path), I wonder if these should be excluded from the chart (not sure what the behaviour is currently).

[ktmud]

A by-thought: if there are many orphaned paths (=both source and target only used in a single path), I wonder if these should be excluded from the chart (not sure what the behavior is currently).

I think they would just be considered part of the flow at the first level. Even though the source might actually be at the second or later level if there's no row limit... That's why a warning about row limit is important.