Implement custom preferences sync

[bvanelli]

Description

See here, Actual allows you to set how your bank sync should work.

The properties are:

• custom-sync-mappings-${acctId}: default is below
• sync-import-pending-${acctId}: if transactions from bank sync with cleared=False should be imported
• sync-import-notes-${acctId}: if notes should be imported or set to null instead

The default mappings are:

export const defaultMappings: Mappings = new Map([
  [
    'payment',
    new Map([
      ['date', 'date'],
      ['payee', 'payeeName'],
      ['notes', 'notes'],
    ]),
  ],
  [
    'deposit',
    new Map([
      ['date', 'date'],
      ['payee', 'payeeName'],
      ['notes', 'notes'],
    ]),
  ],
]);