This commit adds a calendar stream URL to each meetup. The URL is copied to
the clipboard when the user clicks on a new button added to the UI. The copied
URL can be pasted into a compatible calendar app, allowing the user to easily
add the meetup to their calendar. This feature was added to several views
including 'profile/meetups', 'meetup/landing-page', and
'meetup/landing-page-event'. The associated controller 'DownloadMeetupCalendar'
and livewire components were also updated accordingly.