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/models/transaction_import.rb

@@ -0,0 +1,46 @@
+class TransactionImport < Import
+  def import!
+    transaction do
+      mappings.each(&:create_mappable!)
+
+      rows.each do |row|
+        account = mappings.accounts.mappable_for(row.account)
+        category = mappings.categories.mappable_for(row.category)
+        tags = row.tags_list.map { |tag| mappings.tags.mappable_for(tag) }.compact
+
+        entry = account.entries.build \
+          date: row.date_iso,
+          amount: row.signed_amount,
+          name: row.name,
+          currency: row.currency,
+          entryable: Account::Transaction.new(category: category, tags: tags, notes: row.notes),
+          import: self
+
+        entry.save!
+      end
+    end
+  end
+
+  def required_column_keys
+    %i[date amount]
+  end
+
+  def column_keys
+    %i[date amount name currency category tags account notes]
+  end
+
+  def mapping_steps
+    [ Import::CategoryMapping, Import::TagMapping, Import::AccountMapping ]
+  end
+
+  def csv_template
+    template = <<-CSV
+      date*,amount*,name,currency,category,tags,account,notes
+      05/15/2024,-45.99,Grocery Store,USD,Food,groceries|essentials,Checking Account,Monthly grocery run
+      05/16/2024,1500.00,Salary,,Income,,Main Account,
+      05/17/2024,-12.50,Coffee Shop,,,coffee,,
+    CSV
+
+    CSV.parse(template, headers: true)
+  end
+end