MemcachedKeyCharacterError: Control/space characters not allowed

### Problem

```
/openlibrary/openlibrary/templates/type/author/view.html: error in processing template: MemcachedKeyCharacterError: Control/space characters not allowed (key=b'lending.get_availability-"identifier","ADF Project #94000114"') (falling back to default template)
```

https://openlibrary.org/authors/OL341837A/Z._M._Abouguendia

### Reproducing the bug

1. Go to ...
2. Do ...

* Expected behavior:
* Actual behavior:

### Context

- Browser (Chrome, Safari, Firefox, etc):
- OS (Windows, Mac, etc):
- Logged in (Y/N):
- Environment (prod, dev, local): prod

### Breakdown

#### Requirements Checklist
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#### Related files

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#### Stakeholders

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#### Instructions for Contributors

- Please [run these commands](https://github.com/internetarchive/openlibrary/wiki/Git-Cheat-Sheet#working-on-your-branch) to ensure your repository is up to date **before** [creating a new branch](https://github.com/internetarchive/openlibrary/wiki/Git-Cheat-Sheet#making-changes-and-creating-a-pull-request) to work on this issue and **each time after** pushing code to Github, because the pre-commit bot may add commits to your PRs upstream.

Start with templates/type/author/view.html and trace the lending.get_availability lookup that produces the MemcachedKeyCharacterError for the linked author page. Check the cache-key handling and reproduce the page locally; done means the author page renders without this error for identifiers containing spaces or control characters.

Written by the indexing model from the issue text.