feat: add financial mutations resource

[ju5t]

Description

Adds support for the Moneybird Financial Mutations API. Financial mutations are the individual transactions imported from a financial account (bank/credit card); this resource lets you list them, fetch one by id, and link or unlink bookings (payments or ledger account bookings) to process them.

Accessed via the connector:

$connector->financialMutations()->all(perPage: 50, page: 1);
$connector->financialMutations()->get($id);

$booking = Booking::from([
    'booking_type' => 'LedgerAccount',
    'booking_id' => $ledgerAccountId,
    'price' => '10.00',
]);
$connector->financialMutations()->linkBooking($id, $booking);
$connector->financialMutations()->unlinkBooking($id, $booking);

Following the existing resource style, linkBooking/unlinkBooking take a Booking data object rather than a long argument list. All DTO field names and types were verified against the authoritative moneybird/openapi spec.

all() also accepts a Moneybird filter string, and the bulk synchronization endpoints are included (synchronization() for id/version pairs and getByIds() to fetch full records in batches) for pulling more than 100 mutations.

Visual changes

None.

Include translations

• Language files have been updated.

Functional changes

• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.