Upload captured scripts to Coverity Scan for analysis

Coverity Scan 2021.12.1 - to be released on February 13, 2022 - is going to support analysis of Python 3 scripts in addition to current PHP, Python 2, and Ruby ones. I expect the future version of the Coverity Build tool to leverage the --fs-capture-search <path/to/source/code> option and that's what we should add to CI.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information