Changes account names in meta-data strings

[tbm]

Test case:

2022-12-21 * "Test"
  foo: "Assets:Test"
  Assets:Test                           10.00 EUR
  Assets:Test                          -10.00 EUR
  foo: "Assets:Test"

Config:

account_map:
  "Assets:Test": "Assets:Bar"

Output:

2022-12-21 * Test
  ; foo: Assets:Test
  Assets:Bar                                                     10.00 EUR
  Assets:Bar                                                    -10.00 EUR
    ; foo: Assets:Bar

The first foo meta-data stays the same, but the second one is modified - it shouldn't be because it's a string.