Trigger account anonymization from IA

### Feature Request

### Problem / Opportunity

Open Library admins are able to anonymize Open Library accounts, and do so upon patron request. If a patron's account is anonymized in OL, but not deactivated in IA, the patron will not be able to log into OL without error.

To avoid situation like this, it may be nice if OL account anonymizations were triggered by IA when a patron's IA account is closed or anonymized.

https://git.archive.org/ia/petabox/-/merge_requests/5415

### Proposal

1. Remove the ability to anonymize accounts from the OL admin dashboard.
2. Expose endpoint to IA for anonymizing OL accounts.
3. Trigger OL account anonymization whenever a corresponding action is taken on an IA account.

### Breakdown

### Related files

Refer to [this map of common Endpoints](https://github.com/internetarchive/openlibrary/wiki/Endpoints):
* Account [`anonymize` function](https://github.com/internetarchive/openlibrary/blob/e488ef07bedd26415eab8da27d10507c62901ef8/openlibrary/accounts/model.py#L335-L390)

### Requirements Checklist
Checklist of requirements that need to be satisfied in order for this issue to be closed:
* [ ]

### Stakeholders

*

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