Update CI

Run tests as part of CI.

Currently all tests except ceresZMVFNSfastChi2 and chi2scanMTOP are enabled and should pass (running pipeline takes ~1 hour).

xfitter is compiled with all dependencies (including ApplGrid and ROOT dependent reactions).

Installation script was modified, also now it will install numdiff if it is not found.

To install only xfitter dependencies, now one should run:

./tools/install-xfitter deps

(scripts/install-deps.sh was dropped, also directory scripts was dropped)

To have all tests passed, this MR includes !204 (merged) and !208 (merged)