CSV Imports Overhaul (Transactions, Trades, Accounts, and Mint import support) (#1209)

* Remove stale 1.0 import logic and model

* Fresh start

* Checkpoint before removing nav

* First working prototype

* Add trade, account, and mint import flows

* Basic working version with tests

* System tests for each import type

* Clean up mappings flow

* Clean up PR, refactor stale code, tests

* Add back row validations

* Row validations

* Fix import job test

* Fix import navigation

* Fix mint import configuration form

* Currency preset for new accounts

app/controllers/import/configurations_controller.rb

@@ -0,0 +1,25 @@
+class Import::ConfigurationsController < ApplicationController
+  layout "imports"
+
+  before_action :set_import
+
+  def show
+  end
+
+  def update
+    @import.update!(import_params)
+    @import.generate_rows_from_csv
+    @import.reload.sync_mappings
+
+    redirect_to import_clean_path(@import), notice: "Import configured successfully."
+  end
+
+  private
+    def set_import
+      @import = Current.family.imports.find(params[:import_id])
+    end
+
+    def import_params
+      params.require(:import).permit(:date_col_label, :date_format, :name_col_label, :category_col_label, :tags_col_label, :amount_col_label, :signage_convention, :account_col_label, :notes_col_label, :entity_type_col_label)
+    end
+end