Remove use of any map

[jmbrunskill]

Describe the bug

Anymap is not maintained and has a reported security issue.
Even though our use shouldn't be affected this security issue, it would be nice to remove the need for the package

To Reproduce

Steps to reproduce the behaviour:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behaviour

Additional context

chris-morgan/anymap#32
https://github.com/openmsupply/notify/security/dependabot/1