AB#611 - Change flex setting format

[VillePihlava]

Proposed Changes

• Change format to be more clear.
• Add possibility to set transit or direct separately.
• Remove

  // non-direct for testing purposes on planners that only allow direct
  const directFlexOnly =
    config.flex?.directOnlyTaxiJourneys &&
    !window.localStorage.getItem('favouriteStore')?.includes('Flextestaus2025');