import clr with no .NET runtime should give a helpful message #1868
Description
Currently we get
RuntimeError: Could not find libmono
While it is mostly obvious, it would not hurt to expand it to something like
A compatible .NET runtime could not be found. Install a compatible runtime or load one explicitly using
set_runtimeorset_runtime_from_env.
roberto-lopardo-aimen, olichose123, heartacker and qysnn