fix: Convert pval and qval to heatmap (#123)

This PR converts pval and qval in the transcripts view of the diffexp
report from bar plots to heatmaps.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Enhanced visualization of statistical values with heatmap
representations for `pval` and `qval` in both `transcripts` and
`genes_aggregated` datasets.
	- Updated domain values for improved clarity in significance levels.

These changes provide a more detailed and visually informative way to
interpret data significance.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

workflow/resources/datavzrd/diffexp-template.yaml

@@ -211,18 +211,28 @@ views:
  url: "http://www.ensembl.org/Homo_sapiens/Gene/Summary?g={target_id}"
  pval:
  plot:
- bars:
+ heatmap:
  scale: linear
+ range:
+ - "#a1d99b"
+ - "white"
+ - "#fdae6b"
  domain:
- - 0.0
- - 1.0
+ - 0
+ - 0.05
+ - 0.25
  qval:
  plot:
- bars:
+ heatmap:
  scale: linear
+ range:
+ - "#a1d99b"
+ - "white"
+ - "#fdae6b"
  domain:
- - 0.0
- - 1.0
+ - 0
+ - 0.05
+ - 0.25
  test_stat:
  display-mode: hidden 
  rss: