Can't get functions from registry if entry points only points to the correct module and not to the specific functions

I'm getting this extremely odd error that tells me `chain.v1` is not available while it is showing up as available name at the same time.

```python
catalogue.RegistryError: Cant't find 'chain.v1' in registry horizon -> components. Available names: Pipeline.v1, _, chain.v1, fetch.v1, response_to_bytes.v1, response_to_dict.v1, response_to_text.v1
```

I've tried to run my test in debug mode with a break point where the error occurs. If I run `Registry.get` then it fails as in the test but if I run `Registry.get()` a second time then it works.

### Reason

In `Registry.get()` we only look for the specific name, i.e. `from_entry_point = self.get_entry_point(name)` or in the global variable `REGISTRY`. It doesn't exist in either in the first run. But in the second run it does exist in `REGISTRY` since we called `Registry.get_entry_points()` to print the error message, since this method actually load all the modules in the entry points and thereby populates `REGISTRY`.

### Proposed solution

Load all modules from entry points in `Registry.get()` if there is entry points but the requested one is found directly.