Update existing config.jsons with COSMIC connections with new URL

[carolinebridge]

update dataDirLocation uri to https://cancer.sanger.ac.uk/jbrowse/data/json/grch38/v96/gene (/tracklist.json)

Potentially also have to update the config load parser to be looser with JSON restrictions, currently getting an error:

Error: SyntaxError: Unexpected token / in JSON at position 13437 when parsing configuration.

[cmdcolin]

We may want to remove the COSMIC connection from test_data/config.json, it does not work on web (CORS). Could potentially be on desktop only, deployed with products/jbrowse-predefined-sessions

[cmdcolin]

the fact that this URL moves around is a bit concerning for maintainability though, and could be considered to remove entirely also

[cmdcolin]

I went ahead and removed them for now, could do further stuff in https://github.com/GMOD/jbrowse-components/issues/2304