heatmap plotting function is incompatible with toolbox's hide/highlight

[sergpolly]

Description of bug:
built-in heatmap plotting function is incompatible with the MultiQC toolbox, specifically highlight and hide functionality - at times it wouldn't hide anything or wouldn't hide what it is supposed to hide, and highlight seem to "break" heatmap altogether sometimes - please check out screencast for clarification:

in this gif I try to hide SRR pattern (nothing gets hidden apart from broken labels), then undo it, then try to hide other pattern - something "bad" happens)) i undo it; then i try to highlight a couple of groups, first nothing happens, then it "breaks", then I try to sort - it just goes crazy at that point .

MultiQC Error log:
does not apply - it is just an interactive javascript issue

File that triggers the error:
This bug is relevant for any report using the built-in heatmap function - I used "FastQC Status Check" for demonstration: MultiQC_TestData/data/modules/fastqc

MultiQC run details (please complete the following):

• Command used to run MultiQC: multiqc --module fastqc --outdir ./ ./MultiQC_TestData/data/modules/fastqc
• MultiQC Version: v1.9.dev0 (2e16d7e) [latest from master]
• Operating System: Ubuntu 18.04.1
• Python Version: Python 3.7.2
• Method of MultiQC installation: pip

Additional context:
I think i was able to figure it out, so PR is coming ...

[ewels]

Fixed in #1137