TWAS/cTWAS codes needs to support dropping event patterns

Currently impelmented as :

```r
# remove no effect sQTL cluster specific contexts
          if (any(grepl("no_effect_sQTL", twas_weights_results[[gene_db]]$data_type))){
```

which is very specific. We should be using a more general `regex` to screen any patterns in the context names to ignore. 