* refact(e2e): Move Dynamic Host Catalog env to its own file
This keeps each scenario consistent (an env_test.go file in each directory)
* refact(e2e): Update to use type casting
* refact(e2e): Rename existing dynamic host catalog test
* test(e2e): Add test for an empty dynamic host catalog
This test verifies that you fail to connect to a target with an empty host set (in a dynamic host catalog)
* fix(e2e): Update return statement since we know err is nil
* fix(e2e): Add ok checks in type assertions