Use broad cell types + pan-brain reference for deconvolution

[lahuuki]

Update deconvolution strategy Based on 3/12 talk about https://www.biorxiv.org/content/10.1101/2021.01.21.426000v1

• Use pan brain data for reference to up size of reference data
• Use Broad cell types, easier to deconvolute, get more (25) + cleaner marker genes