feat: Support metadata in transaction

Also moves the comment for several converters to original metadata

tests/converters/cbacsv_v0/expected.ledger

@@ -1,45 +1,45 @@
 2025-06-29 ! "Amazon" "Something from Amazon AU"
-    ; AMAZON AU MARKETPLACE    SYDNEY
+    original: "AMAZON AU MARKETPLACE    SYDNEY"
     Liabilities:CBA:CreditCard -70.4 AUD
     Expenses:Shopping:Amazon 70.4 AUD
 
 2025-06-24 * "APIA" "House Insurance"
-    ; APIA                     BRISBANE    QLD
+    original: "APIA                     BRISBANE    QLD"
     Liabilities:CBA:CreditCard -322.39 AUD
     Expenses:House:Insurance 322.39 AUD
 
 2025-06-24 * "CBA" "Bank Fees"
-    ; MONTHLY FEE
+    original: "MONTHLY FEE"
     Liabilities:CBA:CreditCard -8.0 AUD
     Expenses:Fees 8.0 AUD
 
 2025-06-24 * "CBA" "Bank Fees"
-    ; MONTHLY FEE
+    original: "MONTHLY FEE"
     Liabilities:CBA:CreditCard -8.0 AUD
     Expenses:Fees 8.0 AUD
 
 2025-06-17 * "Ergon Energy" "Electricity Bill"
-    ; BPAYN ERGON ENERGY RETAILBPAY
+    original: "BPAYN ERGON ENERGY RETAILBPAY"
     Liabilities:CBA:CreditCard -515.43 AUD
     Expenses:House:Electricity 515.43 AUD
 
 2025-06-15 ! "CBA" "International Transaction Fee"
-    ; INTNL TRANSACTION FEE
+    original: "INTNL TRANSACTION FEE"
     Liabilities:CBA:CreditCard -1.19 AUD
     Expenses:CBA:Fees 1.19 AUD
 
 2025-06-14 ! "CBA" "International Transaction Fee"
-    ; INTNL TRANSACTION FEE
+    original: "INTNL TRANSACTION FEE"
     Liabilities:CBA:CreditCard -8.64 AUD
     Expenses:CBA:Fees 8.64 AUD
 
 2025-06-11 ! "CBA" "International Transaction Fee"
-    ; INTNL TRANSACTION FEE
+    original: "INTNL TRANSACTION FEE"
     Liabilities:CBA:CreditCard -0.86 AUD
     Expenses:CBA:Fees 0.86 AUD
 
 2025-06-04 ! "" "Credit Card Payment"
-    ; PAYMENT RECEIVED, THANK YOU
+    original: "PAYMENT RECEIVED, THANK YOU"
     Assets:OtherBankAccount -2897.86 AUD
     Liabilities:CBA:CreditCard 2897.86 AUD