spin-off from #1298: add tests for options with negative values
It became apparent while working on #1298 (closed) that options can have negative values. Specifically the ones with OPT_INT[0-9]+_TYPE as opposed to OPT_UINT[0-9]+_TYPE.
And it became apparent that we don't have any tests validating that the value is parsed correctly, without errors, etc.
Let's add some.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information