Changes

Use abstract environment to print recmod paths (#14036)

The printing of type cycles with -short-paths previously did not
terminate because it used a typing environment with the physical
cycles. Now, an abstract typing environment is used to print the
types for error messages.

Add error message for abstract types in recmod signatures

This commit adds the origin of abstract types when checking recursive
module signatures. When errors arise due to type checking only with an
abstract module signature, an error message explains why the type was
seen as abstract.