Closes #4

TODO

• reserved or locked currency for deposit/stake for event?
• How do we have anyone allowed to create an event, and the pallet only facilitates they can do this permissionlessly
  • even root cannot directly interfere: only action to dissolve the whole event and return all funds.
• Should we have the host account be separated from a distinct AttendanceOracle origin that could independently be set per event, perhaps defaulting to the host's signed origin. Allows for more nuanced control and separation of concerns (like setting this to a value that a tribunal could override a host in case of dispute)
• Consider a StorageDoubleMap for mapping meetingid & account -> boundedevec allowing for deposits to be mutable on meeting details && be have more confidence the reserved funds can never be miss accounted for.