Extract globals from re-frame state

[aatkin]

Checklist for author

Remove items that aren't applicable, check items that are done.

Reviewability

• [ ] Link to issue
• [ ] Note if PR is on top of other PR
• [ ] Note if related change in rems-deploy repo
• [ ] Consider adding screenshots for ease of review

Backwards compatibility

• [ ] API is backwards compatible or completely new
• [ ] Events are backwards compatible or have migrations
• [ ] Config is backwards compatible
• [ ] Feature appears correctly in PDF print

Documentation

• [ ] Update changelog if necessary
• [ ] API is documented and shows up in Swagger UI
• [ ] Components are added to guide page
• [ ] Update docs/ (if applicable)
• [ ] Update manual/ (if applicable)
• [ ] ADR for major architectural decisions or experiments
• [ ] New config options in config-defaults.edn

Testing

• [ ] Complex logic is unit tested
• [ ] Valuable features are integration / browser / acceptance tested automatically

Follow-up

• [ ] New tasks are created for pending or remaining tasks