Change names of assay types (rnaseq -> counts)

[lianos]

Encoding the assay types as we have now (mainly in construction.R):

.assay.types <- c(
  "rnaseq", "isoseq", "normcounts", "nanostring",
  "qpcrct", "qpcrdct", "lognorm", "raw")

Maybe it's better to simplify:

• rnaseq, isoseq, nanostring -> counts
• lognorm and raw: still ok?
• qpcr(ct|dct): not necessary?

The thinking was to have smarter methods to normalize data when retrieving it with fetch_assay_data(..., normalized = TRUE), but maybe there is a better way.

For instance, we can think about passing in normalization functions to the data container when new assays are added ... deep thoughts ...