fix(dashboards): Use scientific notation for small numbers in breakdown table

[gggritso]

Small number values in the breakdown table below charts showed <0.0001 with a tooltip that displayed 0 for very small values (because toLocaleString() without options rounds aggressively).

This replaces the threshold indicator with scientific notation (e.g., 3.35E-5), which shows the actual value precisely and eliminates the need for a tooltip. This aligns with the number formatting guidelines proposed in #112410 (though, those are in discussion)

Changes:

• formatBreakdownLegendValue now returns scientific notation (3 significant digits) for small number-type values instead of <0.0001
• Removed the <Tooltip> wrapper for small numbers in VisualizationWidget since the value is no longer obfuscated
• Added tests for formatBreakdownLegendValue

I didn't bother changing anything else for this PR, though in the future as we solidify the guidelines we'll implement them more rigorously.

Closes DAIN-1430

[linear-code]

DAIN-1430 Tooltip for small values shows "0"

[DominikB2014]

Code lgtm!
I'm assuming you got design to approve this? I'm wondering if we could do a more dynamic approach, i.e if we can fit the full number do that, otherwise use scientific notation.

[gggritso]

@DominikB2014 it's targeted-ish! Scientific notation is only used for "number" types, only in this table, and only for values <0.0001, so it's just here to cover an edge case. I'm still working with Design Engineering on formatting guidelines for number, this is a little patch fix for now

[DominikB2014]

@DominikB2014 it's targeted-ish! Scientific notation is only used for "number" types, only in this table, and only for values <0.0001, so it's just here to cover an edge case. I'm still working with Design Engineering on formatting guidelines for number, this is a little patch fix for now

Make sense! I meant more so dynamic with available space, but we can figure that with design like u said