Add console1984 and audits1984

To keep as much of this as we can in the `fizzy-saas` gem, this PR
opts to store console/audits models in a separate database, and so:

- the gem contains the migrations and the database config
- the app contains a separate schema file distinctly for SaaS concerns
  - Rails' current behavior prevents us from easily keeping this file in the gem

Also note that the stock `audits1984` schema is updated to reference
the auditor via a UUID foreign key.

Finally, in order for the database schema file to be located in the
gem directory (and not the application directory), it's necessary to
monkeypatch `AR::DatabaseTasks.schema_dump_path` to support absolute
paths. This functionality has been proposed upstream in
https://github.com/rails/rails/pull/56290 but is awaiting a decision
from the core team.

ref: https://app.fizzy.do/5986089/cards/2469
ref: #17

saas/fizzy-saas.gemspec

@@ -35,4 +35,6 @@ Gem::Specification.new do |spec|
   spec.add_dependency "yabeda-puma-plugin"
   spec.add_dependency "yabeda-rails", ">= 0.10"
   spec.add_dependency "prometheus-client-mmap", "~> 1.4.0"
+  spec.add_dependency "console1984"
+  spec.add_dependency "audits1984"
 end