CSV Handling issues and Polish

[lwjameson]

Summary

• Added final(?) spreadsheet templates to /data directory
• Updated annotation CSV import to look for category matches on Tags.
• Fixed handling of empty tag blocks (they showed +-1)
• Fixed margin at the bottom of some screen hiding inputs
• Tested and improved all CSV import and export flows
• Added link to Pages from repo home screen
• Deleted autogenerated Event pages when Event is deleted.
  • There will still be an issue with Custom pages that have embedded events. We will address this in a later update.

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