Start and end balance anchors for historical account balances (#2455)

* Add kind field to valuation

* Fix schema conflict

* Add kind to valuation

* Scaffold opening balance manager

* Opening balance manager implementation

* Update account import to use opening balance manager + tests

* Update account to use opening balance manager

* Fix test assertions, usage of current balance manager

* Lint fixes

* Add Opening Balance manager, add tests to forward calculator

* Add credit card to "all cash" designation

* Simplify valuation model

* Add current balance manager with tests

* Add current balance logic to reverse calculator and plaid sync

* Tweaks to initial calc logic

* Ledger testing helper, tweak assertions for reverse calculator

* Update test assertions

* Extract balance transformer, simplify calculators

* Algo simplifications

* Final tweaks to calculators

* Cleanup

* Fix error, propagate sync errors up to parent

* Update migration script, valuation naming

test/controllers/loans_controller_test.rb

@@ -11,8 +11,8 @@ class LoansControllerTest < ActionDispatch::IntegrationTest
   test "creates with loan details" do
     assert_difference -> { Account.count } => 1,
       -> { Loan.count } => 1,
-      -> { Valuation.count } => 2,
-      -> { Entry.count } => 2 do
+      -> { Valuation.count } => 1,
+      -> { Entry.count } => 1 do
       post loans_path, params: {
         account: {
           name: "New Loan",