Add project root detection for ClojureCLR

[rene-descartes2021]

To get this PR on CIDER to work I have to get clojure-mode to detect the project root for ClojureCLR projects.

bbatsov was right I had to add support here.

I guess the test in the CIDER repo is sufficient so no need to write one here too. I'll look at clojure-ts-mode guess it might be a one line change there too? Well I'll look.

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[bbatsov]

Merged manually after rebasing and resolving the changelog conflict. Thanks!