The `assays(TreatmentResponseExperiment)` method is really slow in WSL2

[ChristopherEeles]

The assays method for a TreatmentResponseExperiment is taking a long time (~4s) to execute on WSL2 with 2 data.table threads.

Need to assess if this occurs on other platforms?

Could possibly speed up the internal joins with colData and rowData by keying the data.tables.

Definitely need to look at improving the speed.

Best,
Chris