Account:: namespace simplifications and cleanup (#2110)

* Flatten Holding model

* Flatten balance model

* Entries domain renames

* Fix valuations reference

* Fix trades stream

* Fix brakeman warnings

* Fix tests

* Replace existing entryable type references in DB

app/models/entryable.rb

@@ -0,0 +1,29 @@
+module Entryable
+  extend ActiveSupport::Concern
+
+  TYPES = %w[Valuation Transaction Trade]
+
+  def self.from_type(entryable_type)
+    entryable_type.presence_in(TYPES).constantize
+  end
+
+  included do
+    has_one :entry, as: :entryable, touch: true
+
+    scope :with_entry, -> { joins(:entry) }
+
+    scope :active, -> { with_entry.merge(Entry.active) }
+
+    scope :in_period, ->(period) {
+      with_entry.where(entries: { date: period.start_date..period.end_date })
+    }
+
+    scope :reverse_chronological, -> {
+      with_entry.merge(Entry.reverse_chronological)
+    }
+
+    scope :chronological, -> {
+      with_entry.merge(Entry.chronological)
+    }
+  end
+end