Enhance the bills extractor

[fabiodrg]

Changes

• CalendarEvent
  • Add support for 'All Day' events
  • Simplify the constructor to reduce number of parameters. Optional parameters such as location, status, ... can be initialised with setters that return the object itself allowing for chaining in constructor invoking
  • Supported in iCalendar out of the box in tested clients (Google, Outlook, Thunderbird, KOrganizer)

    new CalendarEvent(
    title,
    desc,
    isHTML,
    start,
    end
    )
    .setLocation(loc)
    .setStatus(CalendarEventStatus.FREE);

• Update CalendarUrlGenerator to generate URLs that toggle the "All Day" in the event edit form on target platforms (Google, Microsoft, Yahoo)
• Bills extractor
  • Refactor for using the new EventExtractor
  • Correctly calculates the bills amount, including any fees
  • Use modal rather than inline dropdowns
• New extractor for bills with ATM references, BillsPaymentRefs
  • Sort of an extension to the Bills extractor for including ATM reference details
  • It handles cases where multiple bills are associated to the same ATM reference
• Unit tests
  • Better mocking for chrome.storage.local.get, so that Extractor.init completes and initialises with default values
  • Workaround for #90

Preview

"Events Modal" for pending bills and pending bills with ATM references

Events can be created as 'All Day' events, which is more indicated for 'reminder'-like events. Supported in online calendars, like Google, Microsoft and Yahoo. iCalendar formats also working in tested clients

[fabiodrg]

A todo list to complete this PR:

• [x] Finish updating CalendarUrlGenerator to support all day events. I have WIP locally, just need to add support for Yahoo. Will have to create an account for testing xd
• [x] Bills extractor could skip pending bills with generated references, as another extractor will handle them anyway
  • Make it customisable
• [x] Cleanup the CalendarEvent class interface. Improve docs
• [ ] Simplify the unit tests for Bills extractor. Make sure to remove the no-break whitespace from the HTML, which is different from the conventional space character and was causing headaches in strict equals