Multitudes: multiple views, marker layers + area explorer displays per data source

[janbaykara]

This PR reorganises the storage and management of report configuration, to facilitate future roadmap items. It also introduces a few early features based on that refactor.

Closes MAP-935, MAP-923, MAP-911, MAP-931, MAP-817

New features

• Create more than one map views in a report. Closes MAP-817
• Configure the area explorer panel: create multiple displays per layer, more configuration options (e.g. MAP-817). Changes are now persisted to the database.
• Add multiple map markers for a single data source. This is fairly useless right now, but soon we'll add filtering so it will be useful!

Technical changes

• Moves all layer config, except for the source IDs themselves, out of Django's layer DB field and into displayOptions on a per-view basis. This is so that frontend view changes no longer require changes to the GraphQL type system or other backend work. The logic going forwards can be that we only adjust GraphQL types where other backend logic (e.g. data querying) needs to happen anyway.
• Migrates existing displayOptions to a default Map view, adds a rig for versioning displayOptions to allow for further migrations, and adds zod schema resolvers with defaults to enforce and flesh out this config.

Testing

Open a map report and the config should auto-migrate to the new schema. Everything should work as expected. For each layer in the report:

• A marker layer should've been auto-created
• An area explorer should've been auto-created
  And everything should be configurable.

[linear]

MAP-935 Area Explorer display upgrades

MAP-923 Refactor map/layer config

[linear]

MAP-911 Configure multiple displays for a layer

[linear]

MAP-931 Change DataSourceType of BigRecord so you can spoof a person

[linear]

MAP-817 Multiple views to quickly toggle between and create new Choropleth visualisations

[joaquimds]

suggestion: remove this commented out code

[joaquimds]

question: why is this commented out?