Fix/efp relative mode per group control from global control

[VinLau]

So there was an issue with colouring (both absolute [ fixed in #174 ] and now in relative [this fix]). Basically had to:

Problem

The eFP relative color mode and log2 fold change tooltip were using data.control — the average of all group controls across the entire experiment — instead of each tissue's own group.control. This produced incorrect colours and values in any experiment where groups have different controls.

Summary of Fixes:

• Fix the per-group control if it is exists to be the control (Sometimes it is indeed experiment or data wide) hence the ?? operator in Eplant/views/eFP/Viewer/EFPTooltip.tsx
• Make an absolute max for when a group max exists to co-exist with one another
• Pass group control correctly

Before (Note that even the control samples are non-zero [they should always be 0 since its log 2 fold change of 1]):

After:

Details:

Commit 1 — per-group control for relative mode

EFPTooltip.tsx: tooltip log2 fold change now uses group.control (falls back to data.control, then 1)
svg.tsx: useStyles passes group instead of data to getColor, so the relative-mode extremum calculation scales against the group's own min/max and control
legend.tsx: removed unused EFPState import; added a comment noting the legend is a global approximation that may not exactly match per-group colours

Commit 2 — preserve absolute mode scaling

The first commit broke absolute mode: passing group to getColor meant absolute colours normalised against group.max instead of the experiment-wide data.max, making every tissue appear fully red
Added an optional absoluteMax parameter to getColor; absolute mode now uses absoluteMax ?? group.max
useStyles passes data.max as the new argument
legend.tsx unchanged — it already passes data as its group arg, so the fallback resolves correctly

What was NOT changed

The XML parser — group-level tags are parsed correctly
The data shape in types.tsx or the loader in views/eFP/index.tsx — per-group control was already computed correctly; only downstream consumers were ignoring it, so we are just making sure it gets read
The data.control aggregate field — it remains as a fallback

[VinLau]

@Yukthiw @bdls-jamal @mwkyuen can you take a look? I got another PR on top of this, want to keep things up to date.