Data provider simplification, tests, and documentation (#1997)

* Ignore env.test from source control

* Simplification of providers interface

* Synth tests

* Update money to use new find rates method

* Remove unused issues code

* Additional issue feature removals

* Update price data fetching and tests

* Update documentation for providers

* Security test fixes

* Fix self host test

* Update synth usage data access

* Remove AI pr schema changes

test/support/provider_test_helper.rb

@@ -0,0 +1,17 @@
+module ProviderTestHelper
+  def provider_success_response(data)
+    Provider::ProviderResponse.new(
+      success?: true,
+      data: data,
+      error: nil
+    )
+  end
+
+  def provider_error_response(error)
+    Provider::ProviderResponse.new(
+      success?: false,
+      data: nil,
+      error: error
+    )
+  end
+end